Angiotensin System (angiotensin + system)

Distribution by Scientific Domains
Distribution within Medical Sciences

Kinds of Angiotensin System

  • renin angiotensin system


  • Selected Abstracts


    INHIBITION OF BRAIN RENIN,ANGIOTENSIN SYSTEM IMPROVES DIASTOLIC CARDIAC FUNCTION FOLLOWING MYOCARDIAL INFARCTION IN RATS

    CLINICAL AND EXPERIMENTAL PHARMACOLOGY AND PHYSIOLOGY, Issue 8 2009
    IG Araujo
    SUMMARY 1Recently, we demonstrated that oral captopril treatment improved diastolic function and attenuated cardiac remodelling after myocardial infarction (MI) in rats. Considering the feasible role of the brain renin,angiotensin system (RAS) in heart failure, in the present study we investigated the role of the captopril injected intracerebroventricularly (i.c.v.) on the progression of cardiac dysfunction. 2Male Wistar rats underwent experimental MI or sham operation. Infarcted animals received daily i.c.v. injections of captopril (approximately 200 mg/kg; MI + Cap) or saline (MI) from 11 to 18 days after infarction. Electro- and echocardiogram assessments were performed before and after i.c.v. treatment (10 and 18 days after MI, respectively). Water and hypertonic saline ingestion were determined daily between 12 and 16 days after MI. 3Electrocardiograms from the MI and MI + Cap groups showed signs that resembled large MI before and after i.c.v. treatment. However, despite similar systolic dysfunction observed in both groups, only captopril-treated rats exhibited reduced left ventricular (LV) dilatation and improved LV filling, as assessed by echocardiograms, and low levels of water ingestion compared with the saline-treated control group. 4The results of the present study suggest that the brain RAS may participate in the development of cardiac dysfunction induced by ischaemia and that inhibition of the brain RAS may provide a new strategy for the prevention of diastolic dysfunction. [source]


    TNF Alpha,308 Genotype and Renin,Angiotensin System in Hemodialysis Patients: An Effect on Inflammatory Cytokine Levels?

    ARTIFICIAL ORGANS, Issue 2 2005
    Gultekin Genctoy
    Abstract:, Background: Renin,angiotensin system (RAS) was suggested to modulate inflammatory cytokine production. Angiotensin II was consistently shown to increase production of tumor necrosis factor alpha (TNF-,). However, inflammatory cytokines and RAS were modulated by genetic polymorphisms such as TNF-,,308 G > A and angiotensin-converting enzyme (ACE) I/D gene polymorphisms. The aim of this study was to investigate the effects of ACE and TNF-, genotypes on inflammatory cytokines in hemodialysis (HD) patients. Methods: ACE I/D and TNF-,,308 G > A genotypes, pre- and postdialysis plasma renin activity (PRA), serum ACE, interleukin-1 beta (IL-1,), and TNF-, levels were determined in 22 HD patients. Results: Predialysis serum ACE activity is correlated with TNF-, (r = 0.63; P = 0.01), and PRA was correlated with IL-1, levels (r = 0.49; P = 0.02). Pre/postdialysis IL-1, and TNF-, were similar in DD and II/ID ACE genotypes. Predialysis TNF-, and IL-1, (32.4 ± 5; 35.1 ± 4.2 vs. 28.1 ± 3.7; 26.5 ± 6.2 pg/mL; P < 0.05) and postdialysis TNF-, levels (30.4 ± 1.4 vs. 28.4 ± 0.82 pg/mL; P < 0.05) were significantly higher in TNF1/2 than TNF1/1 patients. Conclusion: ACE and TNF-,,308 G > A (1/2) gene polymorphisms may contribute to modulation of proinflammatory cytokine production and hence chronic inflammation in HD patients. [source]


    Acute exercise causes an enhancement of tissue renin,angiotensin system in the kidney in rats

    ACTA PHYSIOLOGICA, Issue 1 2005
    S. Maeda
    Abstract Aims:, Initially, the renin,angiotensin system (RAS) produced through the classical endocrine pathway was well known for its regulation of blood pressure. However, it was revealed that a local autocrine and/or paracrine RAS may exist in a number of tissues (such as kidney). Exercise causes a redistribution of tissue blood flow, by which the blood flow is greatly increased in active muscles, whereas it is decreased in the splanchnic circulation (such as in the kidney). We hypothesized that exercise causes an enhancement of tissue RAS in the kidney. Methods:, We studied whether exercise affects expression of angiotensinogen and angiotensin-converting enzyme (ACE) and tissue angiotensin II level in the kidney. The rats performed treadmill running for 30-min. Immediately after this exercise, kidney was quickly removed. Control rats remained at rest during this 30-min period. Results:, The expression of angiotensinogen mRNA in the kidney was markedly higher in the exercise rats than in the control rats. ACE mRNA in the kidney was significantly higher in the exercise rats than in the control rats. Western blot analysis confirmed significant upregulation of ACE protein in the kidney after exercise. Tissue angiotensin II level was also increased by exercise. Conclusion:, The present study suggests that the exercise-induced enhancement of tissue RAS in the kidney causes vasoconstriction and hence decreases blood flow in the kidney, which are helpful in increasing blood flow in active muscles, thereby contributing to the redistribution of blood flow during exercise. [source]


    Exploring type I angiotensin (AT1) receptor functions through gene targeting

    ACTA PHYSIOLOGICA, Issue 4 2004
    S. D. Crowley
    Abstract The renin,angiotensin system (RAS) modulates a diverse set of physiological processes including development, blood pressure, renal function and inflammation. The principal effector molecule of this system, angiotensin II, mediates most of these actions. The classically recognized functions of the RAS are triggered via the type 1 (AT1) class of angiotensin receptors. Pharmacological blockade of the AT1 receptor lowers blood pressure and slows the progression of cardiovascular and renal diseases. Gene-targeting technology provides an experimental approach for precisely dissecting the physiological functions of the RAS. Here, we review how gene-targeting experiments have elucidated AT1 receptor functions. [source]


    Transgenic mice for studies of the renin,angiotensin system in hypertension

    ACTA PHYSIOLOGICA, Issue 4 2004
    J. L. Lavoie
    Abstract Hypertension is a polygenic and multi-factorial disorder that is extremely prevalent in western societies, and thus has received a great deal of attention by the research community. The renin,angiotensin system has a strong impact on the control of blood pressure both in the short- and long-term, making it one of the most extensively studied physiological systems. Nevertheless, despite decades of research, the specific mechanisms implicated in its action on blood pressure and electrolyte balance, as well as its integration with other cardiovascular pathways remains incomplete. The production of transgenic models either over-expressing or knocking-out specific components of the renin,angiotensin system has given us a better understanding of its role in the pathogenesis of hypertension. Moreover, our attention has recently been refocused on local tissue renin,angiotensin systems and their physiological effect on blood pressure and end-organ damage. Herein, we will review studies using genetic manipulation of animals to determine the role of the endocrine and tissue renin,angiotensin system in hypertension. We will also discuss some untraditional approaches to target the renin,angiotensin system in the kidney. [source]


    Treatment of diabetic hypertension

    DIABETES OBESITY & METABOLISM, Issue 5 2009
    David S. H. Bell
    Insulin resistance and hyperglycaemia combine to make hypertension more prevalent in the type 2 diabetic patient. Blood pressure goals below those for the non-diabetic subject have been shown to be more effective in lowering mortality and cardiovascular events in the diabetic patient. To achieve these goals in most cases, three to five antihypertensives from different therapeutic groups need to be utilized. Suppression of the renin,angiotensin system (RAS) with angiotensin-converting enzyme inhibitors, angiotensin 2 receptor blockers or a renin inhibitor should be the primary therapy. A second goal should be suppression of the sympathetic nervous system utilizing a beta-blocker that does not increase insulin resistance. The addition of a diuretic, calcium channel blocker or a vasodilator to suppressors of the RAS and sympathetic nervous system aid in achieving hypertensive goals in the diabetic patient. Achieving hypertensive goals with suppression of the RAS and sympathetic nervous system should result in a decrease in mortality and cardiovascular events in the diabetic hypertensive patient. In this review article, the benefits and disadvantages of the different antihypertensive therapies in the diabetic patient are discussed. [source]


    Cardiovascular drugs as antidiabetic agents: evidence for the prevention of type 2 diabetes

    DIABETES OBESITY & METABOLISM, Issue 7 2008
    D. P. Macfarlane
    Given the long-term health consequences and increasing incidence of type 2 diabetes, there is great interest to potentially prevent or delay its onset. Primary prevention studies have demonstrated that intensive exercise and weight reduction, and to a lesser extent certain antidiabetic agents, can reduce new onset diabetes in at-risk individuals. Results from post hoc analyses and secondary end-point outcomes of large randomized controlled trials of cardiovascular drugs suggest that these may also have beneficial effects, reducing the incidence of new onset diabetes in addition to their proven cardiovascular benefits. Multiple meta-analyses confirm that drugs primarily acting on the renin,angiotensin system (RAS) reduce the incidence of diabetes in the populations studied, perhaps via improved insulin sensitivity and/or effects on pancreatic beta cells. However, results from the recent Diabetes REduction Approaches with Medication study specifically failed to show a significant reduction in the incidence of diabetes with ramipril in individuals with abnormal glucose tolerance at baseline. There is only limited evidence that statins improve glucose tolerance, and although beta-blockers tend to have detrimental effects on glucose tolerance, newer agents with vasodilatory properties may confer benefits. With current guidelines, the use of cardiovascular drugs modifying the RAS will increase in at-risk individuals, but at present, they cannot be recommended to prevent diabetes. [source]


    ,-Blocker use and diabetes symptom score: results from the GEMINI study

    DIABETES OBESITY & METABOLISM, Issue 3 2007
    J. B. McGill
    Aim:, The Glycemic Effect in Diabetes Mellitus: Carvedilol,Metoprolol Comparison in Hypertensives (GEMINI) trial compared the metabolic effects of two ,-blockers in people with type 2 diabetes and hypertension treated with renin,angiotensin system (RAS) blockade and found differences in metabolic outcomes. In this paper, we report the results of a prespecified secondary analysis of GEMINI that sought to determine the effect of these two ,-blockers on commonly reported symptoms. Methods:, The Diabetes Symptom Checklist (DSC), a self-report questionnaire measuring the occurrence and perceived burden of diabetes-related symptoms, was completed by GEMINI participants at baseline and at the end of the study (maintenance month 5). The DSC assessed symptoms in eight domains: psychology (fatigue), psychology (cognitive), neuropathy (pain), neuropathy (sensory), cardiology, ophthalmology, hyperglycaemia and hypoglycaemia. Results:, Comparison of the mean change in self-reported diabetes-related symptoms indicated a significant treatment difference favouring carvedilol over metoprolol tartrate in overall symptom score (,0.08; 95% CI ,0.15, ,0.01; p = 0.02) and in the domains for hypoglycaemia symptoms (,0.12; 95% CI ,0.23, ,0.02; p = 0.02) and hyperglycaemia symptoms (,0.16; 95% CI ,0.27, ,0.05; p = 0.005). Carvedilol resulted in fewer perceived diabetes-related symptoms in patients with diabetes and hypertension. Conclusion:, Carvedilol resulted in a lower perceived burden of diabetes-related symptoms in patients with type 2 diabetes and hypertension. The addition of a well-tolerated ,-blocker to RAS blockade may improve hypertension treatment and quality of life in patients with diabetes. [source]


    Inhibition of the renin,angiotensin system: added value in reducing cardiovascular and renal risk?

    DIABETIC MEDICINE, Issue 1 2004
    S. M. Marshall
    No abstract is available for this article. [source]


    The renin,angiotensin system and the long-term complications of diabetes: pathophysiological and therapeutic considerations

    DIABETIC MEDICINE, Issue 8 2003
    R. E. Gilbert
    Abstract The relationship between the renin,angiotensin system (RAS) and the progression of diabetic renal disease has been a major focus of investigation over the past 20 years. More recently, experimental and clinical studies have also suggested that the RAS may have a pathogenetic role at other sites of micro- and macrovascular injury in diabetes. Complementing major advances into the understanding of the local, as distinct from the systemic RAS, a number of large clinical trials have examined whether blockade of the RAS might provide protection from the long-term complications of diabetes, beyond that due to blood pressure reduction alone. While some controversy remains, these studies have, in general, suggested that angiotensin converting enzyme (ACE) inhibition and more recently, angiotensin receptor blockade reduce the development and progression of diabetic nephropathy, cardiovascular disease and possibly retinopathy. This review will focus on recent developments in our understanding of the tissue-based RAS and its role in end-organ injury in diabetes, the results of recent clinical trials and newer strategies for the pharmacological manipulation of the RAS. [source]


    ACE and angiotensinogen gene genotypes and left ventricular mass in athletes

    EUROPEAN JOURNAL OF CLINICAL INVESTIGATION, Issue 10 2001
    F. Diet
    Background Genetic factors may be important in modifying heart size due to long-term athletic training. The significance of polymorphisms of genes of the renin,angiotensin system in myocardial mass in a population of athletes participating in different disciplines is not known. Methods The angiotensin I-converting enzyme gene insertion/deletion (I/D) polymorphism, angiotensinogen gene M235T polymorphism and angiotensin II type 1 receptor gene A1166C polymorphism were determined in 83 male Caucasian endurance athletes and associated with left ventricular mass. Results No association with left ventricular mass was found for the polymorphisms of angiotensin I-converting enzyme gene I/D, angiotensinogen gene M235T and angiotensin II type 1 gene A1166C when studied separately. However, combined analysis of the angiotensin I-converting enzyme gene I/D polymorphism and angiotensinogen gene M235T polymorphism genotypes suggested an association with left ventricular mass (g m,2) (P = 0·023). Athletes with the angiotensin I-converting enzyme gene DD/angiotensinogen gene TT genotype combination had greater left ventricular mass compared with all other genotype combinations (179·8 ± 26·1 g m,2 vs. 145·2 ± 27·3 g m,2, P = 0·003). Conclusions These results suggest an association of combined angiotensin I-converting enzyme gene I/D polymorphism genotypes, and angiotensinogen gene M235T polymorphism genotypes with left ventricular hypertrophy due to long-term athletic training. A synergistic effect of angiotensin I-converting enzyme gene DD genotype and angiotensinogen gene TT genotype on left ventricular mass in endurance athletes appears to occur. [source]


    Angiotensin-converting enzyme genotype and encephalopathy in Chernobyl cleanup workers

    EUROPEAN JOURNAL OF NEUROLOGY, Issue 1 2009
    A. D. Kehoe
    Background and purpose:, To identify, using a genetic model, a key role for the renin,angiotensin system (RAS) in the development of dyscirculatory encephalopathy (DE) in Chernobyl cleanup workers (CCW). The insertion/deletion polymorphism of the angiotensin-converting enzyme (ACE) gene denotes a substantial individual variation in RAS activity with the D-allele being associated with higher ACE activity. Methods:, Ninety-three male, Caucasian CCW were recruited from those under regular review at the All-Russia Centre of Emergency and Radiation Medicine, St. Petersburg. The presence or absence of DE was determined using existing institutional guidelines. ACE genotype was determined using internationally accepted methodologies. Results:, Angiotensin-converting enzyme genotype distribution in 59 subjects with DE was II: 10 (17%), ID: 31 (53%), DD: 18 (30%), D-allele frequency 56.8%. Whereas in those without the condition the distribution was II: 12 (35%), ID: 19 (56%), DD 3 (9%) and D-allele frequency 35.9% (P = 0.02). Conclusions:, These data are the first to identify an association between the ACE D-allele and DE in CCW. They provide evidence of a significant role for the RAS in the development of DE and suggest that clinical trials of ACE inhibition would be profitable in this group. [source]


    Human skin: source of and target organ for angiotensin II

    EXPERIMENTAL DERMATOLOGY, Issue 3 2004
    U. Muscha Steckelings
    Abstract:, The present study examined the expression of angiotensin receptors in human skin, the potential synthesis of angiotensin II (Ang II) in this location and looked for a first insight into physiological functions. AT1 and AT2 receptors were found within the epidermis and in dermal vessel walls. The same expression pattern was found for angiotensinogen, renin and angiotensin-converting enzyme (ACE). All components could additionally be demonstrated at mRNA level in cultured primary keratinocytes, melanocytes, dermal fibroblasts and dermal microvascular endothelial cells, except for AT2 receptors in melanocytes. The ability of cutaneous cells to synthesize Ang II was proved by identifying the molecule in cultured keratinocytes. Furthermore, in artificially wounded keratinocyte monolayers, ACE-mRNA expression was rapidly increased, and enhanced ACE expression was still found in cutaneous human scars 3 months after wounding. These findings suggest that the complete renin,angiotensin system is present in human skin and plays a role in normal cutaneous homeostasis as well as in human cutaneous wound healing. [source]


    Candesartan pretreatment is cerebroprotective in a rat model of endothelin-1-induced middle cerebral artery occlusion

    EXPERIMENTAL PHYSIOLOGY, Issue 8 2009
    Adam P. Mecca
    Endogenous levels of angiotensin II (Ang II) are increased in the cortex and hypothalamus following stroke, and Ang II type 1 receptor blockers (ARBs) have been shown to attenuate the deleterious effects in animal stroke models using middle cerebral artery (MCA) intraluminal occlusion procedures. However, the endothelin-1 (ET-1)-induced middle cerebral artery occlusion (MCAO) model of cerebral ischaemia is thought to more closely mimic the temporal events of an embolic stroke. This method provides rapid occlusion of the MCA and a gradual reperfusion that lasts for 16,22 h. The aim of the present study was to evaluate whether systemic administration of an ARB prior to ET-1-induced MCAO would provide cerebroprotection during this model of ischaemic stroke. Injection of 3 ,l of 80 ,m ET-1 adjacent to the MCA resulted in complete occlusion of the vessel that resolved over a period of 30,40 min. Following ET-1-induced MCAO, rats had significant neurological impairment, as well as an infarct that consisted of 30% of the ipsilateral grey matter. Systemic pretreatment with 0.2 mg kg,1 day,1 candesartan for 7 days attenuated both the infarct size and the neurological deficits caused by ET-1-induced MCAO without altering blood pressure. This study confirms the cerebroprotective properties of ARBs during ischaemic stroke and validates the ET-1-induced MCAO model for examination of the role of the brain renin,angiotensin system in ischaemic stroke. [source]


    Recent advances in the renin,angiotensin system: angiotensin-converting enzyme 2 and (pro)renin receptor

    EXPERIMENTAL PHYSIOLOGY, Issue 5 2008
    Mohan K. Raizada
    No abstract is available for this article. [source]


    Functional angiotensin-converting enzyme 2 is expressed in human cardiac myofibroblasts

    EXPERIMENTAL PHYSIOLOGY, Issue 5 2008
    Jodie L. Guy
    The renin,angiotensin system (RAS), in particular angiotensin II, plays an important role in cardiac remodelling. Angiotensin-converting enzyme (ACE) and angiotensin-converting enzyme 2 (ACE2) are key players in the RAS and act antagonistically to regulate the levels of angiotensin II. In this study, we reveal the functional expression of ACE2 in human cardiac myofibroblasts, cells that are essential to the maintenance of normal cardiac architecture and also play a key role in myocardial remodelling. The observed reciprocal expression of ACE and ACE2 in these cells may reflect the possible opposing activity of these two enzymes. In this study, we demonstrate the presence of ACE2 as an ectoenzyme and reveal that ACE2 undergoes phorbol-12-myristate-13-acetate-inducible ectodomain shedding from the membrane. When cells were exposed to a number of pathophysiological stimuli, modulation of ACE2 levels was not detected. Importantly, whilst we found ACE2 to be expressed constitutively in cardiac myofibroblasts there were no detectable levels in either vascular smooth muscle cells or vascular endothelium, indicating that ACE2 expression is not ubiquitous. In paraffin sections of atrial appendage tissue, we observed a distinct staining pattern for ACE2 which appeared different from that of ACE. In conclusion, this study is the first to report co-expression of ACE and ACE2 in human cardiac myofibroblasts and may therefore present a model primary system for study of the comparative cell biology of ACE2 and ACE and their potentially opposing roles in myocardial remodelling. [source]


    Tissue-specific regulation of ACE/ACE2 and AT1/AT2 receptor gene expression by oestrogen in apolipoprotein E/oestrogen receptor-, knock-out mice

    EXPERIMENTAL PHYSIOLOGY, Issue 5 2008
    K. Bridget Brosnihan
    Angiotensin-converting enzyme (ACE) and ACE2 and the AT1 and AT2 receptors are pivotal points of regulation in the renin,angiotensin system. ACE and ACE2 are key enzymes in the formation and degradation of angiotensin II (Ang II) and angiotensin-(1,7)(Ang-(1,7)). Ang II acts at either the AT1 or the AT2 receptor to mediate opposing actions of vasoconstriction or vasodilatation respectively. While it is known that oestrogen acts to downregulate ACE and the AT1 receptor, its regulation of ACE2 and the AT2 receptor and the involvement of a specific oestrogen receptor subtype are unknown. To investigate the role of oestrogen receptor-, (ER,) in the regulation by oestrogen of ACE/ACE2 and AT1/AT2 mRNAs in lung and kidney, ovariectomized female mice lacking apolipoprotein E (ee) with the ER, (AAee) or without the ER, (,,ee) were treated with 17,-oestradiol (6 ,g day,1) or placebo for 3 months. ACE, ACE2, AT1 receptor and AT2 receptor mRNAs were measured using reverse transcriptase, real-time polymerase chain reaction. In the kidney, 17,-oestradiol showed 1.7-fold downregulation of ACE mRNA in AAee mice, with 2.1-fold upregulation of ACE mRNA in ,,ee mice. 17,-Oestradiol showed 1.5- and 1.8-fold downregulation of ACE2 and AT1 receptor mRNA in AAee mice; this regulation was lost in ,,ee mice. 17,-Oestradiol showed marked (81-fold) upregulation of the AT2 receptor mRNA in AAee mice. In the lung, 17,-oestradiol treatment had no effect on AT1 receptor mRNA in AAee mice, but resulted in a 1.5-fold decreased regulation of AT1 mRNA in ,,ee mice. There was no significant interaction of oestrogen with ER, in the lung for ACE, ACE2 and AT2 receptor genes. These studies reveal tissue-specific regulation by 17,-oestradiol of ACE/ACE2 and AT1/AT2 receptor genes, with the ER, receptor being primarily responsible for the regulation of kidney ACE2, AT1 receptor and AT2 receptor genes. [source]


    Contribution of endothelium-derived hyperpolarizing factors to the regulation of vascular tone in humans

    FUNDAMENTAL & CLINICAL PHARMACOLOGY, Issue 4 2008
    Jeremy Bellien
    Abstract Endothelium plays a crucial role in the regulation of cardiovascular homeostasis through the release of vasoactive factors. Besides nitric oxide (NO) and prostacyclin, increasing evidences show that endothelium-derived hyperpolarizing factors (EDHF) participate in the control of vasomotor tone through the activation of calcium-activated potassium channels. In humans, the role of EDHF has been demonstrated in various vascular beds including coronary, peripheral, skin and venous vessels. The mechanisms of EDHF-type relaxations identified in humans involved the release by the endothelium of hydrogen peroxide, epoxyeicosatrienoic acids (EETs), potassium ions and electronical communication through the gap junctions. The role of EETs could be particularly important because, in addition contributing to the maintenance of the basal tone and endothelium-dependent dilation of conduit arteries, these factors share many vascular protective properties of NO. The alteration of which might be involved in the physiopathology of cardiovascular diseases. The evolution of EDHF availability in human pathology is currently under investigation with some results demonstrating an increase in EDHF release to compensate the loss of NO synthesis and to maintain the endothelial vasomotor function whereas others reported a parallel decrease in NO and EDHF-mediated relaxations. Thus, the modulation of EDHF activity emerges as a new pharmacological target and some existing therapies in particular those affecting the renin,angiotensin system have already been shown to improve endothelial function through hyperpolarizing mechanisms. In this context, the development of new specific pharmacological agents especially those increasing EETs availability may help to prevent endothelial dysfunction and therefore enhance cardiovascular protection in patients. [source]


    Systemic infusion of angiotensin II exacerbates liver fibrosis in bile duct,ligated rats,

    HEPATOLOGY, Issue 5 2005
    Ramón Bataller
    Recent evidence indicates that the renin,angiotensin system (RAS) plays a major role in liver fibrosis. Here, we investigate whether the circulatory RAS, which is frequently activated in patients with chronic liver disease, contributes to fibrosis progression. To test this hypothesis, we increased circulatory angiotensin II (Ang II) levels in rats undergoing biliary fibrosis. Saline or Ang II (25 ng/kg/h) were infused into bile duct,ligated rats for 2 weeks through a subcutaneous pump. Ang II infusion increased serum levels of Ang II and augmented bile duct ligation,induced liver injury, as assessed by elevated liver serum enzymes. Moreover, it increased the hepatic concentration of inflammatory proteins (tumor necrosis factor , and interleukin 1,) and the infiltration of CD43-positive inflammatory cells. Ang II infusion also favored the development of vascular thrombosis and increased the procoagulant activity of tissue factor in the liver. Livers from bile duct,ligated rats infused with Ang II showed increased transforming growth factor ,1 content, collagen deposition, accumulation of smooth muscle ,-actin,positive cells, and lipid peroxidation products. Moreover, Ang II infusion stimulated phosphorylation of c-Jun and p42/44 mitogen-activated protein kinase and increased proliferation of bile duct cells. In cultured rat hepatic stellate cells (HSCs), Ang II (10,8 mol/L) increased intracellular calcium and stimulated reactive oxygen species formation, cellular proliferation and secretion of proinflammatory cytokines. Moreover, Ang II stimulated the procoagulant activity of HSCs, a newly described biological function for these cells. In conclusion, increased systemic Ang II augments hepatic fibrosis and promotes inflammation, oxidative stress, and thrombogenic events. (HEPATOLOGY 2005;41:1046,1055.) [source]


    The renin,angiotensin system as a primary cause of polyarteritis nodosa in rats

    JOURNAL OF CELLULAR AND MOLECULAR MEDICINE, Issue 6a 2010
    Barbara S. Peters
    Abstract Polyarteritis nodosa is a necrotizing vasculitis of medium-sized arteries of unknown origin. Hypertension is present in 30% of patients with polyarteritis nodosa. In those cases, high renin levels are thought to be secondary to renal involvement. The present study was performed to identify causal factors of polyarteritis nodosa. In cyp1a1ren-2 transgenic rats, vasculitis of medium-sized arteries resembling classical polyarteritis nodosa can be induced. In this model, oral administration of indole-3-carbinol (I3C) activates the liver-specific cyp1a1 promoter, leading to prorenin expression in a dose-dependent manner. After the first 6 weeks of chronic induction with 0.125% I3C, the mean arterial pressure reached a plateau of about 170 mmHg. Ten out of 11 I3C-treated rats, which were chronically instrumented with a telemetric device to measure blood pressure, developed polyarteritis nodosa within 10 weeks of I3C treatment. I3C alone or instrumentation alone did not cause polyarteritis nodosa. The angiotensin-converting enzyme inhibitor captopril completely prevented the development of polyarteritis nodosa, indicating that local angiotensin II generation is a pathogenetic factor in this model. The renin,angiotensin system can play a primary role in the development of polyarteritis nodosa in rats. [source]


    Angiotensin II/angiotensin II type I receptor (AT1R) signaling promotes MCF-7 breast cancer cells survival via PI3-kinase/Akt pathway

    JOURNAL OF CELLULAR PHYSIOLOGY, Issue 1 2010
    Yanbin Zhao
    Angiotensin II (Ang II) is a bioactive peptide of the renin,angiotensin system, acting not only as a vasoconstrictor but also as a growth promoter via angiotensin II type 1 receptor (AT1R) in some cancer. In this study, we examined the mechanisms by which Ang II affected the cell proliferation in AT1R-positive MCF-7 human breast cancer cells. Ang II stimulated the growth of breast cancer cells in a dose- and time-dependent manner. The maximal proliferation effect on MCF-7 cells was obtained with 10,4,M Ang II at 24,h. Losartan (10,5,M, an AT1R antagonist) significantly decreased the level of Ang-II-induced proliferative effects, whereas PD123319 (10,5,M, an AT2R antagonist) had no effects. Moreover, Ang II could significantly accelerate S-phase progression, which was inhibited by losartan (10,5,M) or LY294002 (50,µM, a PI3-kinase inhibitor). In addition, Ang II caused rapid activation of p-Akt in a dose- and time-dependent manner. 10,4,M Ang II induced a significant increase of p-Akt in 15,min. The peak level of p-Akt could be persisted for at least 6,h. Among the signaling molecules downstream of Akt, we revealed that Ang II also significantly upregulated CyclinD1, GSK3,, and downregulated p27. Pretreatment with losartan (10,5,M) or LY294002 (50,µM) could significantly suppress these effects of Ang II. These findings suggest that Ang II plays a role in the growth of AT1R-positive breast cancer cells through PI3-kinase/Akt pathway activation. Therefore, targeting Ang II/AT1R signaling could be a novel therapeutic for breast cancer. J. Cell. Physiol. 225: 168,173, 2010. © 2010 Wiley-Liss, Inc. [source]


    Captopril and its synthesis from chiral intermediates

    JOURNAL OF CHEMICAL TECHNOLOGY & BIOTECHNOLOGY, Issue 2 2001
    R Chirumamilla
    Abstract Captopril is an antihypertensive agent that inhibits the angiotensin-converting enzyme of the renin,angiotensin system. Chiral intermediates are used in the synthesis of the drug. These intermediates are obtained by resolution of racemic compounds or by chemical, biocatalytic methods and or by asymmetric synthesis by biocatalytic process. This article reviews the various chemical and biochemical processes involved in the synthesis of the chiral drug, including the pharmacological action of captopril. © 2001 Society of Chemical Industry [source]


    Liver disease and the renin,angiotensin system: Recent discoveries and clinical implications

    JOURNAL OF GASTROENTEROLOGY AND HEPATOLOGY, Issue 9 2008
    John S Lubel
    Abstract The renin,angiotensin system (RAS) is a key regulator of vascular resistance, sodium and water homeostasis and the response to tissue injury. Historically, angiotensin II (Ang II) was thought to be the primary effector peptide of this system. Ang II is produced predominantly by the effect of angiotensin converting enzyme (ACE) on angiotensin I (Ang I). Ang II acts mainly through the angiotensin II type-1 receptor (AT1) and, together with ACE, these components represent the ,classical' axis of the RAS. Drug therapies targeting the RAS by inhibiting Ang II formation (ACE inhibitors) or binding to its receptor (angiotensin receptor blockers) are now in widespread clinical use and have been shown to reduce tissue injury and fibrosis in cardiac and renal disease independently of their effects on blood pressure. In 2000, two groups using different methodologies identified a homolog of ACE, called ACE2, which cleaves Ang II to form the biologically active heptapeptide, Ang-(1,7). Conceptually, ACE2, Ang-(1,7), and its putative receptor, the mas receptor represent an ,alternative' axis of the RAS capable of opposing the often deleterious actions of Ang II. Interestingly, ACE inhibitors and angiotensin receptor blockers increase Ang-(1,7) production and it has been proposed that some of the beneficial effects of these drugs are mediated through upregulation of Ang-(1,7) rather than inhibition of Ang II production or receptor binding. The present review focuses on the novel components and pathways of the RAS with particular reference to their potential contribution towards the pathophysiology of liver disease. [source]


    Atrial fibrillation: insights from clinical trials and novel treatment options

    JOURNAL OF INTERNAL MEDICINE, Issue 6 2007
    Y. Blaauw
    Abstract., Blaauw Y, Crijns HJGM (University Hospital Maastricht, Maastricht, The Netherlands). Atrial fibrillation: insights from clinical trials and novel treatment options (Review). J Intern Med 2007; 262: 593,614. Atrial fibrillation (AF) is the most common encountered sustained arrhythmia in clinical practice. The last decade the result of large ,rate' versus ,rhythm' control trials have been published that have changed the current day practise of AF treatment. It has become clear that rate control is at least equally effective as a rhythm control strategy in ameliorating morbidity as well as mortality. Moreover, in each individual patient the risk of thromboembolic events should be assessed and antithrombotic treatment be initiated. There have also been great advances in understanding the mechanisms of AF. Experimental studies showed that as a result of electrical and structural remodelling of the atria, ,AF begets AF'. Pharmacological prevention of atrial electrical remodelling has been troublesome, but it seems that blockers of the renin angiotensin system, and perhaps statins, may reduce atrial structural remodelling by preventing atrial fibrosis. Clinical studies demonstrated that the pulmonary veins exhibit foci that can act as initiator and perpetuator of the arrhythmia. Isolation of the pulmonary veins using radiofrequency catheter ablation usually abolishes AF. The most promising advances in the pharmacological treatment of AF include atrial specific antiarrhythmic drugs and direct thrombin inhibitors. In the present review we will describe the results of recent experimental studies, discuss the latest clinical trials, and we will focus on novel treatment modalities. [source]


    Human brain aminopeptidase A: biochemical properties and distribution in brain nuclei

    JOURNAL OF NEUROCHEMISTRY, Issue 1 2008
    Nadia De Mota
    Abstract Aminopeptidase A (APA) generated brain angiotensin III, one of the main effector peptides of the brain renin angiotensin system, exerting a tonic stimulatory effect on the control of blood pressure in hypertensive rats. The distribution of APA in human brain has not been yet studied. We first biochemically characterized human brain APA (apparent molecular mass of 165 and 130 kDa) and we showed that the human enzyme exhibited similar enzymatic characteristics to recombinant mouse APA. Both enzymes had similar sensitivity to Ca2+. Kinetic studies showed that the Km (190 ,mol/L) of the human enzyme for the synthetic substrate- l -glutamyl-,-naphthylamide was close from that of the mouse enzyme (256 ,mol/L). Moreover, various classes of inhibitors including the specific and selective APA inhibitor, (S)-3-amino-4-mercapto-butyl sulfonic acid, had similar inhibitory potencies toward both enzymes. Using (S)-3-amino-4-mercapto-butyl sulfonic acid, we then specifically measured the activity of APA in 40 microdissected areas of the adult human brain. Significant heterogeneity was found in the activity of APA in the various analyzed regions. The highest activity was measured in the choroids plexus and the pineal gland. High activity was also detected in the dorsomedial medulla oblongata, in the septum, the prefrontal cortex, the olfactory bulb, the nucleus accumbens, and the hypothalamus, especially in the paraventricular and supraoptic nuclei. Immunostaining of human brain sections at the level of the medulla oblongata strengthened these data, showing for the first time a high density of immunoreactive neuronal cell bodies and fibers in the motor hypoglossal nucleus, the dorsal motor nucleus of the vagus, the nucleus of the solitary tract, the Roller nucleus, the ambiguus nucleus, the inferior olivary complex, and in the external cuneate nucleus. APA immunoreactivity was also visualized in vessels and capillaries in the dorsal motor nucleus of the vagus and the inferior olivary complex. The presence of APA in several human brain nuclei sensitive to angiotensins and involved in blood pressure regulation suggests that APA in humans is an integral component of the brain renin angiotensin system and strengthens the idea that APA inhibitors could be clinically tested as an additional therapy for the treatment of certain forms of hypertension. [source]


    Oestrogenic Regulation Of Brain Angiotensinogen

    JOURNAL OF NEUROENDOCRINOLOGY, Issue 6 2004
    K. J. Greenland
    Abstract Oestrogens are now recognized as playing a regulatory role on components of the systemic renin,angiotensin system, such as its precursor, angiotensinogen (AGT). In the brain, this role is poorly understood. The aim of this study was to investigate the influence of oestrogens on brain AGT of female rats at different stages of the oestrous cycle, in pregnancy and following ovariectomy with and without hormone replacement. AGT content of different brain regions was also studied in male rats treated with oestrogens. The brain was divided into five regions: cortex, cerebellum, brainstem, midbrain and thalamus/hypothalamus, and AGT was measured by direct radioimmunoassay using a highly specific AGT antibody. Cyclical fluctuations in AGT content were observed in all regions except the cerebellum over the course of the 4-day oestrous cycle, with peak concentrations at estrus and lowest concentrations at metestrus. Following ovariectomy, brain AGT was significantly decreased in the thalamic/hypothalamic region, an effect that was reversed by oestrogen-replacement. In pregnant rats, AGT contents were elevated in the brainstem region. Oestrogen treatment of male rats induced significant increases in AGT concentrations in all areas except the cortex. In summary, these results show that oestradiol has actions on brain AGT that are region-specific and dependent on the particular physiological and reproductive context. Moreover, the changes in AGT concentrations in the oestrous cycle suggest the involvement of other factors besides oestrogen. Finally, this study supports the view that the brain renin,angiotensin system has a broad role in oestrogen-modulated brain functions beyond those specific to the hypothalamic,pituitary,ovarian axis. [source]


    Potential roles of melatonin and chronotherapy among the new trends in hypertension treatment

    JOURNAL OF PINEAL RESEARCH, Issue 2 2009
    Fedor Simko
    Abstract:, The number of well-controlled hypertensives is unacceptably low worldwide. Respecting the circadian variation of blood pressure, nontraditional antihypertensives, and treatment in early stages of hypertension are potential ways to improve hypertension therapy. First, prominent variations in circadian rhythm are characteristic for blood pressure. The revolutionary MAPEC (Ambulatory Blood Pressure Monitoring and Cardiovascular Events) study, in 3000 adult hypertensives investigates, whether chronotherapy influences the cardiovascular prognosis beyond blood pressure reduction per se. Second, melatonin, statins and aliskiren are hopeful drugs for hypertension treatment. Melatonin, through its scavenging and antioxidant effects, preservation of NO availability, sympatholytic effect or specific melatonin receptor activation exerts antihypertensive and anti-remodeling effects and may be useful especially in patients with nondipping nighttime blood pressure pattern or with nocturnal hypertension and in hypertensives with left ventricular hypertrophy (LVH). Owing to its multifunctional physiological actions, this indolamine may offer cardiovascular protection far beyond its hemodynamic benefit. Statins exert several pleiotropic effects through inhibition of small guanosine triphosphate-binding proteins such as Ras and Rho. Remarkably, statins reduce blood pressure in hypertensive patients and more importantly they attenuate LVH. Addition of statins should be considered for high-risk hypertensives, for hypertensives with LVH, and possibly for high-risk prehypertensive patients. The direct renin inhibitor, aliskiren, inhibits catalytic activity of renin molecules in circulation and in the kidney, thus lowering angiotensin II levels. Furthermore, aliskiren by modifying the prorenin conformation may prevent prorenin activation. At present, aliskiren should be considered in hypertensive patients not sufficiently controlled or intolerant to other inhibitors of renin,angiotensin system. Third, TROPHY (Trial of Preventing Hypertension) is the first pharmacological intervention for prehypertensive patients revealing that treatment with angiotensin II type 1 receptor blocker attenuates hypertension development and thus decreases the risk of cardiovascular events. [source]


    Effect of renin,angiotensin system inhibitors on prevention of peritoneal fibrosis in peritoneal dialysis patients

    NEPHROLOGY, Issue 1 2010
    SUN JING
    ABSTRACT: Aim: Long-term peritoneal dialysis (PD) may lead to peritoneal fibrosis and ultrafiltration failure. It had been demonstrated that the renin,angiotensin system (RAS) plays a key role in the regulation of peritoneal function in rats on PD. We investigated the effects of angiotensin-converting enzyme inhibitor (ACEI) or angiotensin receptor blocker (ARB) on long-term PD patients. Methods: We analyzed data from 66 patients treated with PD therapy at our centre for at least 12 months retrospectively, during which time at least two peritoneal equilibration tests (PET) were performed. Thirty-eight patients were treated with ACE/angiotensin II (AII) inhibitors (ACE/ARB group); the other 28 received none of the above drugs during the entire follow up (control group). The expression of fibronectin, transforming growth factor-,1 (TGF-,1), Aquaporin1 (AQP1) and vascular endothelial growth factor (VEGF) in the overnight effluent were examined by enzyme-linked immunosorbent assay. Results: The demographic data of the two groups showed no difference during the study. No difference between the groups was found with respect to residual renal function (RRF) at the start for both groups by the end of follow up, decreased in the vast majority of patients from both groups (P = 0.014). After 12 months, a significant difference in ultrafiltration was found between the two groups: in the control group it had decreased, while it had not changed in the ACE/ARB group (P < 0.05). In comparison with the baseline level, expression of fibronectin, TGF-,1 and VEGF in dialysate effluent were significantly increased except for AQP1 in the control group (P < 0.05), but not in the ACE/ARB group (P > 0.05). Conclusion: The findings suggest that ACE/AII inhibitors appeared to have a slower rate of decline in ultrafiltration and RRF, effectively protect against peritoneal fibrosis in long-term peritoneal dialysis. Long-term follow up seems to be required to draw more conclusions. [source]


    Animal models of fetal renal disease

    PRENATAL DIAGNOSIS, Issue 11 2001
    Craig A. Peters
    Abstract Fetal models of urinary tract disease have been used for many years and have provided unique and important insights into the pathophysiology of these conditions. This review will summarize the principal model systems used and the current directions of investigation. These models (including rabbit, opossum, sheep and recently swine) have demonstrated that in utero obstruction of the urinary tract alters renal growth, differentiation and produces stereotypical patterns of tissue response, particularly fibrosis. New molecular understanding of these processes has identified specific mechanisms that may be key elements in the development of renal dysfunction due to obstruction. These factors include the renin,angiotensin system (RAS) and its interaction with TGF-, in altering growth regulation and tissue fibrosis. These factors offer the prospect of clinical utility as markers of disease progression as well as pharmacologic therapy. Gene knockout systems have opened a new horizon of molecular models of congenital obstructive uropathy with insights into the role of the RAS in particular. It remains to be defined how closely these knockouts represent the human conditions they resemble. Continued application of fetal models of urinary obstruction, integrating large animal and knockout systems offers promise for improved diagnosis and treatment in these challenging conditions. Copyright © 2001 John Wiley & Sons, Ltd. [source]


    Latest news and product developments

    PRESCRIBER, Issue 22 2007
    Article first published online: 28 DEC 200
    Glitazones: benefits outweigh the risks Following a review of the safety of rosiglitazone and pioglitazone, the European Medicines Agency (EMEA) has concluded that their benefits outweigh their risks in the approved indications. The review was prompted by reports of an increased risk of fractures in women and, in patients taking rosiglitazone, ischaemic heart disease. The EMEA concluded that prescribing information for rosiglitazone should now include a warning that, in patients with ischaemic heart disease, it should only be used after careful evaluation of each patient's individual risk, and the combination of rosiglitazone and insulin should only be used in exceptional cases and under close supervision. No change was considered necessary to the prescribing information for pioglitazone. Modern dressings no better? A systematic review has found only weak evidence that modern dressings are better than saline gauze or paraffin gauze for healing acute and chronic wounds (Arch Dermatol 2007;143: 1297-304). The analysis, which included 99 studies, found that only hydrocolloids were demonstrably better than older dressings for healing chronic wounds, and alginates were superior to other modern dressings for debriding necrotic wounds. There was no evidence that modern dressings offered superior overall performance to the older alternatives. Hospital inflation twice primary care level The cost of drugs prescribed in secondary care but dispensed in the community increased by 6.4 per cent in 2006 - twice the rate of inflation in primary care - according to the latest statistics on hospital prescribing in England. The increase follows a reduction in costs in 2005 after the introduction of the new PPRS scheme. Data from The Information Centre (www.ic.nhs.uk) show that hospital medicines make up about 24 per cent of the NHS drugs budget. Secondary care has a consistently better record than primary care in prescribing lower-cost alternatives within therapeutic categories, eg simvastatin and pravastatin among the statins, omeprazole and lansoprazole among PPIs, and ACE inhibitors among drugs acting on the renin angiotensin system. The most expensive drug prescribed by hospital specialists and dispensed in the community is interferon beta. MHRA limits the use of fibrates The Medicines and Healthcare products Regulatory Agency (MHRA) has advised that fibrates should now be reserved for the treatment of isolated severe hypertriglyceridaemia. They should be considered for hypercholesterolaemia only when a statin or other treatment is contraindicated or not tolerated. In the latest Drug Safety Update, the MHRA says there is insufficient evidence of long-term benefits from fibrates, and first-line use is no longer justified because the evidence for the benefits of statins is robust. The MHRA also warns that some breastfeeding infants have increased susceptibility to the adverse effects of codeine taken by their mother, and that St John's wort may affect the hepatic metabolism of any anticonvulsant. Annual zoledronic acid infusion cuts mortality after hip fracture Once-yearly infusion of zoledronic acid (Aclasta) after hip fracture reduces deaths over a two-year period by 28 per cent compared with placebo, US investigators say (N Engl J Med 2007;357:1799-809). The HORIZON Recurrent Fracture Trial randomised 2127 men and women (mean age 75) within 90 days of surgery for hip fracture to zoledronic acid 5mg yearly or placebo. Mortality over 1.9 years of follow-up was 9.6 per cent with zoledronic acid and 13.3 per cent with placebo. Zoledronic acid also significantly reduced the rate of any new clinical fractures (by 35 per cent) and new clinical vertebral fractures(by 45 per cent),but the lower rate of hip fracture (2.0 vs 3.5 per cent with placebo) was not statistically significant. Rivastigmine patch for mild to moderate AD Rivastigmine (Exelon) is now available as a transdermal patch for the treatment of mild to moderate Alzheimer's disease. Applied once daily, the patch delivers 9.5mg per 24 hours and, says manufacturer Novartis, is associated with a lower incidence of nausea and vomiting than a comparable oral dose. The patch is available in two strengths: 4.6mg per 24hr is equivalent to oral doses of 3 or 6mg per day, and the 9.5mg per 24hr patch is equivalent to 9 or 12mg per day orally. The recommended dose of the patch is 9.5mg per day; both strengths cost £83.84 for 30 patches. Women more aspirin resistant than men? The cardioprotective effect of low-dose aspirin may be lower in women than men, say Canadian investigators (BMC Medicine 2007;5:29 doi: 10.1186/1741-70155-29). Their meta-analysis of 23 randomised trials involving a total of 113 494 participants found that aspirin significantly reduced the risk of nonfatal but not fatal myocardial infarction (MI). About one-quarter of the variation in its effects on nonfatal MI was accounted for by the sex mix of the trial population. Separating the results by sex showed the reduction in risk with aspirin use was statistically significant in men (relative risk, RR, 0.62) but not in women (RR 0.87). Look after physical health of mentally ill GPs and other primary care workers should take more responsibility for the physical health of their mentally ill patients, say advocacy groups. Mind and Body: Preventing and Improving Physical Health Problems in Patients With Schizophrenia points out that the mental health needs of patients with schizophrenia are met in secondary care, but their physical health needs should be met in primary care. In particular, the metabolic effects of antipsychotics may lead to obesity, diabetes and cardiovascular disease, and weight gain in particular is a frequent reason for nonadherence to treatment. The Mind and Body Manifesto was developed by SANE, The Mental Health Nurses Association, The National Obesity Forum and The Disability Rights Commission and sponsored by Bristol-Myers Squibb Pharmaceuticals Limited and Otsuka Pharmaceuticals (UK) Ltd. Copies are available from elizabeth.green@ ogilvyhealthworld.com. Health eCard costs Some costs quoted in our article on the Health eCard (The Health eCard: the way ahead for medical records?,5 October issue, pages 28-9) have been revised: the card and initial download will cost patients £39.50, and GPs will be entitled to charge patients £10 per annum for subsequent downloads. NICE appraisals of cytokine inhibitors in RA NICE has endorsed the use of the anti-TNF agents adalimumab (Humira), etanercept (Enbrel) and infliximab (Remicade), normally in conjunction with methotrexate, for the treatment of active RA when methotrexate and another DMARD have failed (also see New from NICE below). NICE has provisionally concluded, subject to consultation, that abatacept (Orencia) should not be recommended for the treatment of RA. Boots and BMJ launch health advice site www.askbootshealth.com is a new website providing information about health and medicines for the public produced by Boots using information provided by the BMJ Publishing Group. The website covers many of the topics already available from NHSDirect, with perhaps more information about available treatments. Diabetes care shows small improvement The third National Diabetes Audit in England and Wales has found that more people with diabetes were achieving the targets set by NICE for cholesterol levels, glycaemic control and blood pressure in 2005/06 - but younger patients were doing less well. Overall, the HbA1C target of ,7.5 per cent was achieved in 60 per cent of people with diabetes compared with 58 per cent in 2004/05. However, HbA1C was >9.5 per cent in 30 per cent of children and young people, of whom 9 per cent experienced at least one episode of ketoacidosis. More topics for NICE New topics referred to NICE include clinical guidelines on ovarian cancer, coeliac disease and stable angina, public health guidance on preventing cardiovascular disease, and technology appraisals on insulin detemir (Levemir) for type 1 diabetes, several treatments for cancer and hepatic and haematological disorders, and biological therapies for juvenile arthritis. New from NICE NICE appraisal on anti-TNFs for RA Since NICE published its first appraisal of agents acting against tumour necrosis factor-alpha (anti-TNFs) for the treatment of RA in 2002, the product licences for etanercept (Enbrel) and infliximab (Remicade) have changed and a new agent, adalimumab (Humira), has been introduced. The anti-TNFs act in different ways. Infliximab is a chimeric monoclonal antibody that binds to TNF-alpha, neutralising its activity. Etanercept, a recombinant human TNF-alpha receptor fusion protein, and adalimumab, a human-sequence antibody, both bind to TNF-alpha and block its interaction with cell surface receptors. Adalimumab also modulates some biological responses induced or regulated by TNF-alpha. These agents are recommended for adults with severe active RA (defined as a disease activity score - DAS28 - greater than 5.1) who have already tried two disease-modifying drugs, including methotrexate (if not contraindicated). Prior treatment should have been of at least six months' duration, including two months at the standard dose (unless limited by toxicity). Anti-TNFs should normally be prescribed with methotrexate; when this is not appropriate, etanercept and adalimumab may be prescribed as monotherapy. Treatment with an anti-TNF should be continued beyond six months only if there is an adequate response (defined as an improvement in DAS28 of at least 1.2). Data from the British Rheumatology Society Biologics register show that, after six months, 67 per cent of patients met NICE criteria for an adequate response; this declined to 55 per cent at 18 months. The basic annual cost of treatment is £9295 for adalimumab 40mg on alternate weeks or etanercept 25mg twice weekly; infliximab costs £3777 for a loading dose, then £7553-£8812 depending on dose. Assuming no progression of disability, the incremental costs per QALY (compared with sequential DMARDs) were £30 200 for adalimumab, £24 600 for etanercept and £39 400 for infliximab. There are no direct comparative trials of the anti-TNFs, and their clinical trial findings are not directly comparable. Unless other factors determine treatment choice, NICE therefore recommends the least expensive. If the first anti-TNF is withdrawn within six months due to an adverse event, a second may be tried. [source]