Home About us Contact
|
Home About us Contact | ||
|
|
||
eNOS
Terms modified by eNOS Selected AbstractsRole of shear stress on nitrite and NOS protein content in different size conduit arteries of swineACTA PHYSIOLOGICA, Issue 2 2009X. Guo Abstract Aim:, Inherent fundamental difference exists among arteries of different sizes. The purpose of this study was to evaluate the relation between regional difference of wall shear stress (WSS) in various sizes arteries and contents of nitrite and NO synthase (NOS) isoforms. Methods:, Five different conduit arteries in a wide range of diameter (1,8 mm) were examined in the hind limbs of 13 pigs. Blood flow rate and outer diameter were measured in vivo to determine WSS. Arterial tissues were harvested for the measurement of nitrite and NOS protein contents. The concentration of nitrite, a product of NO synthesis, was determined by high-performance liquid chromatography method. Western blot analysis was used to assess the protein contents of endothelial NOS (eNOS), inducible NOS (iNOS) and neuronal NOS (nNOS). Results:, Our data show that WSS increases with a decrease in artery diameter. Nitrite level increases with increasing WSS and hence decreases with artery diameter. The eNOS protein contents decrease with an increase in diameter. No significant difference for iNOS and nNOS protein contents was found with different artery diameter. A significant positive correlation between tissue nitrite and eNOS protein contents was also observed. Finally, the WSS-normalized eNOS is not significantly different in various size vessels. Conclusion:, Regional difference in blood flow has no effect on iNOS and nNOS protein contents in these conduit arteries. Regional difference in eNOS expression and nitrite contents may be related to the WSS-induced NO by the endothelium under normal physiological conditions. [source] Nitric oxide counteracts angiotensin II induced contraction in efferent arterioles in miceACTA PHYSIOLOGICA, Issue 4 2004A. Patzak Abstract Aim:, Efferent arterioles (Ef) are one of the final control elements in glomerular haemodynamics. The influence of nitric oxide (NO) on Ef remains ambiguous. Methods:, To test the hypothesis that endothelial NO plays an important role in this context, afferent arterioles (Af) and Ef of wild-type mice (WT), and Ef of mice lacking the endothelial NO synthetase [eNOS(,/,)] were perfused. Perfusion was performed in Ef via Af (orthograde) as well as from the distal end of Ef (retrograde), which provides an estimate for the importance of substances derived from the glomerulus. Angiotensin II (Ang II) was added in doses ranging from 10,12 to 10,6 mol L,1 to the bath solution. Results:, Ang II reduced the luminal diameter of Af to 68 ± 7 and in Ef to 55 ± 8% during orthograde, and to 35 ± 6% during retrograde perfusion (10,6 mol L,1 Ang II) in WT. Pre-treatment with NG -Nitro- l -arginine-methylester (l -NAME) (10,4 mol L,1) increased the Ang II sensitivity in retrograde (17 ± 9%) and orthograde perfused Ef (19 ± 9%). The Ang II sensitivity was enhanced in eNOS(,/,) mice compared with WT, too. Already at a dose of Ang II 10,9 mol L,1, luminal diameters diminished to 8 ± 7 and 7 ± 4%. Conclusion:, The increased Ang II sensitivity during l -NAME pre-treatment and in eNOS(,/,) mice indicates a strong counteraction of endothelial derived NO on Ang II induced contraction in Ef. Moreover, Ef are similarly sensitive to Ang II during either retrograde or orthograde perfusion in the absence of NO effects, suggesting that NO mediates, at least in part, the action of potential vasodilatory substances from the glomerulus. [source] Endothelially Derived Nitric Oxide Affects the Severity of Early Acetaminophen-induced Hepatic Injury in MiceACADEMIC EMERGENCY MEDICINE, Issue 5 2006Steven D. Salhanick MD Abstract Objectives: The precise mechanism of hepatocellular toxicity following acetaminophen (APAP) poisoning remains unclear. Nitric oxide is implicated in APAP toxicity as an inflammatory signaling molecule and as a precursor to the free radical peroxynitrate. The effects of inducible nitric oxide synthase (iNOS)-derived NO in APAP toxicity are known; however, the role of endothelial nitric oxide synthase (eNOS)-derived NO is unknown. The authors sought to evaluate the effect of eNOS-derived NO during APAP toxicity. Methods: C57BL6/J mice deficient in eNOS (eNOS KO) or iNOS (iNOS KO) and wild-type mice (WT) were treated with 300 mg/kg APAP. Alanine aminotransferase levels and plasma nitrate and nitrite levels were measured. Hypoxia inducible factor (HIF)-1, and Glucose Transporter 1 (Glut-1) levels were determined by Western blot. Results: Alanine aminotransferase levels were significantly elevated in all treated animals. Alanine aminotransferase levels were significantly lower in eNOS KO and iNOS KO than in treated WT animals. Plasma nitrate/nitrite levels were significantly higher in WT animals than in iNOS KO and eNOS KO animals. HIF-1, expression was increased in WT mice and decreased in iNOS KO mice. Glut-1 is a downstream, indirect marker of HIF function. Glut-1 expression was increased in WT and eNOS KO mice. Conclusions: Deficiency of either iNOS or eNOS results in decreased NO production and is associated with reduced hepatocellular injury following APAP poisoning. HIF-1, and Glut-1 levels are increased following APAP poisoning, implying that HIF-1, is functional during the pathogenic response to APAP poisoning. [source] Fatty acid incorporation in endothelial cells and effects on endothelial nitric oxide synthaseEUROPEAN JOURNAL OF CLINICAL INVESTIGATION, Issue 9 2007S. Couloubaly Abstract Background The nature of fatty acids provided by the diet as well as plasma lipid metabolism can modify the composition and properties of plasma membrane and thus the activity of membrane proteins. In humans, as well as in experimental models, diabetes is associated with both an alteration in serum lipid profile and a documented endothelial dysfunction. This in vitro study investigated on an immortalized human endothelial cell line (EA.hy 926) the specific effects of several free fatty acids (FFAs) on the composition of cellular membranes and the regulation of endothelial nitric oxide synthase (eNOS). Materials and methods 0·1% of lipid deprived serum was added to the incubation medium with 25 mm glucose in order to study the effects of individual fatty acids: myristic acid, palmitic acid, stearic acid, oleic acid or linoleic acid at 100 µm bound with albumin. The effects of the FFAs on the endothelial nitric oxide synthase were investigated on mRNA level by quantitative PCR, on protein level and Ser1177 phosphorylation by Western blot and on enzymatic activity on living cells using radiolabelled arginine. Results Free linoleic acid increased the membrane content in n-6 fatty acids (mainly C18: n-6 and its metabolites) with a decrease in saturated and monounsaturated fatty acids. These conditions decreased the basal eNOS activity and reduced the phosphorylation of eNOS-Ser1177 due to activation by histamine. Free palmitic acid enriched the membranes with 16 : 0 with a slight decrease in monounsaturated fatty acids. These conditions increased eNOS activation without increasing Ser1177 phosphorylation upon histamine activation. The addition of the other FFAs also resulted in modifications of membrane composition, which did not to affect eNOS-Ser1177 phosphorylation. Conclusion Among the fatty acids used, only modification of the membrane composition due to linoleic acid supply disturbed the basal enzymatic activity and Ser1177 phosphorylation of eNOS in a way that limited the role of histamine activation. Linoleic acid might involve the dysfunction of both eNOS basal activity and its phosphorylation status and may then contribute to an impaired vasodilatation in vivo. [source] A 4-trifluoromethyl derivative of salicylate, triflusal, stimulates nitric oxide production by human neutrophils: role in platelet functionEUROPEAN JOURNAL OF CLINICAL INVESTIGATION, Issue 9 2000De Miguel Background The thrombotic process is a multicellular phenomenon in which not only platelets but also neutrophils are involved. Recent in vitro studies performed in our laboratory have demonstrated that triflusal, a 4-trifluoromethyl derivative of salicylate, reduced platelet aggregation not only by inhibiting thromboxane A2 production but also by stimulating nitric oxide (NO) generation by neutrophils. The aim of the present study was to evaluate whether oral treatment of healthy volunteers with triflusal could modify the ability of their neutrophils to produce NO and to test the role of the NO released by neutrophils in the modulation of ADP-induced platelet aggregation and ,-granule secretion. Methods The study was performed in 12 healthy volunteers who were orally treated with triflusal (600 mg day,1) for 5 days. Flow cytometric detection of platelet surface expression of P-selectin was used as a measure of the ability of platelets to release the contents of their ,-granules. Results After treatment with triflusal, there was an increase in NO production by neutrophils and an increase in endothelial nitric oxide synthase (eNOS) protein expression in neutrophils. A potentiation of the inhibition of platelet aggregation by neutrophils was reversed by incubating neutrophils with both an l -arginine antagonist, NG -nitro- l -arginine methyl ester ( l -NAME) and an NO scavenger, 2-(4-carboxyphenyl)-4,4,5,5 tetramethylimidazoline 1-oxyl 3-oxide (C-PTIO). A slight decrease in P-selectin surface expression on platelets was found which was not modified by the presence of neutrophils and therefore by the neutrophil-derived NO. Exogenous NO released by sodium nitroprusside dose-dependently inhibited both ADP-stimulated ,-granule secretion and platelet aggregation. Therefore, platelet aggregation showed a greater sensitivity to be inhibited by exogenous NO than P-selectin expression. Conclusion Oral treatment of healthy volunteers with triflusal stimulated NO production and eNOS protein expression in their neutrophils. After triflusal treatment, the neutrophils demonstrated a higher ability to prevent ADP-induced platelet aggregation. However, the neutrophils and the endogenous NO generated by them failed to modify P-selectin expression in ADP-activated platelets. [source] The effect of ultraviolet B irradiation on nitric oxide synthase expression in murine keratinocytesEXPERIMENTAL DERMATOLOGY, Issue 6 2000M. Sasaki Abstract: Nitric oxide (NO), which has several physiological functions in skin, is generated by NO synthase (NOS). NOS has at least three isoforms; endothelial NOS (eNOS), brain NOS (bNOS), and inducible NOS (iNOS). Ultraviolet B (UVB) irradiation has been reported to stimulate NO production in skin via induction or activation of NOS, however, the exact mechanism of NOS induction by UVB irradiation remains obscure. In this study, we investigated the direct effect of UVB on the expression of NOS isoforms in murine keratinocytes, and found a significant increase in NO production within 48 h. mRNA and protein expressions of bNOS were both enhanced by UVB irradiation in murine keratinocytes, whereas iNOS mRNA expression was suppressed at 4 and 12 h after UVB irradiation. These results suggest that the enhancement of NO production observed after UVB irradiation in murine keratinocytes may be explained in part by the upregulation of bNOS expression, but not iNOS expression. [source] Somatic Gene Transfer: Implications for Cardiovascular ControlEXPERIMENTAL PHYSIOLOGY, Issue 6 2000S. Kasparov There is a great need for closer integration between physiologists and molecular biologists. These two research fields might soon form a single research discipline under the umbrella of molecular physiology. One of the areas where this interaction may be particularly fruitful is with somatic gene transfer using replication-deficient viral vectors. We applied this approach to study the central control of the cardiovascular system at the level of the nucleus of the solitary tract (NTS). We assess critically this new methodology as applied to experiments in an integrative environment (such as the whole animal). The usefulness of in vivo gene transfer is illustrated by an experiment where viral gene delivery helped to circumvent the problem imposed by an absence of a specific pharmacological blocker of the enzyme, endothelial nitric oxide synthase (eNOS). The pros and cons of using adenoviral vectors as opposed to conventional pharmacological approaches are discussed. We conclude that the use of adenoviruses to manipulate genes offers a new avenue for physiologists studying neuronal mechanisms in integrative models. [source] Possible role of exogenous cAMP to improve vascular endothelial dysfunction in hypertensive ratsFUNDAMENTAL & CLINICAL PHARMACOLOGY, Issue 6 2006Dhvanit I. Shah Abstract The study has been designed to investigate the effect of 8-Br-cAMP, an activator of protein kinase A, in hypertension-induced vascular endothelial dysfunction. Rats were uninephroctomized and desoxycortisone acetate (DOCA) (40 mg/kg, s.c.) was administered to rats to produce hypertension (mean arterial blood pressure > 140 mmHg). Vascular endothelial dysfunction was assessed using isolated aortic ring preparation, electron microscopy of thoracic aorta and serum concentration of nitrite/nitrate. The expression of mRNA for p22phox and eNOS was assessed by using reverse transcriptase-polymerase chain reaction. Serum thiobarbituric acid reactive substances concentration and aortic superoxide anion concentration were estimated to assess oxidative stress. 8-Br-cAMP (5 mg/kg, i.p.) or atorvastatin (30 mg/kg, p.o.) prevented hypertension-induced attenuation of acetylcholine-induced endothelium-dependent relaxation, impairment of vascular endothelial lining, decrease in expression of mRNA for endothelial nitric oxide synthase (eNOS), serum nitrite/nitrate concentration and increase in expression of mRNA for p22phox, superoxide anion and serum TBARS. The ameliorative effect of 8-Br-cAMP was prevented by N -nitro- l -arginine methyl ester (25 mg/kg, i.p.) and glibenclamide (30 mg/kg, i.p.). It may be concluded that 8-Br-cAMP may stimulate expression and activity of eNOS and suppress expression of p22phox subunit of NADPH oxidase to reduce oxidative stress and subsequently improve vascular endothelial dysfunction. [source] Insulin resistance, a new target for nitric oxide-delivery drugsFUNDAMENTAL & CLINICAL PHARMACOLOGY, Issue 6 2002Stéphane Cook Abstract In the Western hemisphere, the incidence of insulin resistance and its complications has been growing rapidly and is reaching epidemic proportions. Over the past decade, evidence has accumulated, indicating that nitric oxide (NO) plays a key role in the regulation of metabolic and cardiovascular homeostasis. Defective endothelial nitric oxide synthase (eNOS) driven NO synthesis causes insulin resistance, arterial hypertension and dyslipidemia in mice, and characterizes insulin-resistant humans. On the other hand, stimulation of inducible nitric oxide synthase (iNOS) and NO overproduction in mice, may also cause metabolic insulin resistance, suggesting a Yin,Yang effect of NO in the regulation of glucose homeostasis. Here, we will review the evidence for this novel concept, and thereby provide the conceptual framework for the use of NO-delivery drugs and pharmacological agents that modulate the bioavailability of endogenously produced NO for the treatment of insulin resistance. [source] A role for asymmetric dimethylarginine in the pathophysiology of portal hypertension in rats with biliary cirrhosis,,HEPATOLOGY, Issue 6 2005Wim Laleman Reduced intrahepatic endothelial nitric oxide synthase (eNOS) activity contributes to the pathogenesis of portal hypertension (PHT) associated with cirrhosis. We evaluated whether asymmetric dimethylarginine (ADMA), a putative endogenous NOS inhibitor, may be involved in PHT associated with cirrhosis. Two rat models of cirrhosis (thioacetamide [TAA]-induced and bile duct excision [BDE]-induced, n = 10 each), one rat model of PHT without cirrhosis (partial portal vein,ligated [PPVL], n = 10), and sham-operated control rats (n = 10) were studied. We assessed hepatic NOS activity, eNOS protein expression, plasma ADMA levels, and intrahepatic endothelial function. To evaluate intrahepatic endothelial function, concentration,effect curves of acetylcholine were determined in situ in perfused normal rat livers and livers of rats with TAA- or BDE-induced cirrhosis (n = 10) that had been preincubated with either vehicle or ADMA; in addition, measurements of nitrite/nitrate (NOx) and ADMA were made in perfusates. Both models of cirrhosis exhibited decreased hepatic NOS activity. In rats with TAA-induced cirrhosis, this decrease was associated with reduced hepatic eNOS protein levels and immunoreactivity. Rats with BDE-induced cirrhosis had eNOS protein levels comparable to those in control rats but exhibited significantly higher plasma ADMA levels than those in all other groups. In normal perfused liver, ADMA induced impaired endothelium-dependent vasorelaxation and reduced NOx perfusate levels, phenomena that were mimicked by NG -nitro- L -arginine-methyl ester. In contrast to perfused livers with cirrhosis induced by TAA, impaired endothelial cell-mediated relaxation in perfused livers with cirrhosis induced by BDE was exacerbated by ADMA and was associated with a decreased rate of removal of ADMA (34.3% ± 6.0% vs. 70.9% ± 3.2%). In conclusion, in rats with TAA-induced cirrhosis, decreased eNOS enzyme levels seem to be responsible for impaired NOS activity; in rats with biliary cirrhosis, an endogenous NOS inhibitor, ADMA, may mediate decreased NOS activity. (HEPATOLOGY 2005;42:1382,1390.) [source] The role of endothelin-1 and the endothelin B receptor in the pathogenesis of hepatopulmonary syndrome in the ratHEPATOLOGY, Issue 6 2004Yiqun Ling Endothelin-1 (ET-1) stimulation of endothelial nitric oxide synthase (eNOS) via pulmonary endothelial endothelin B (ETB) receptors and pulmonary intravascular macrophage accumulation with expression of inducible nitric oxide synthase (iNOS) and heme oxygenase-1 (HO-1) are implicated in experimental hepatopulmonary syndrome (HPS) after common bile duct ligation (CBDL). Our aim was to evaluate the role of ET-1 in the development of experimental HPS. The time course of molecular and physiological changes of HPS and the effects of selective endothelin receptor antagonists in vivo were assessed after CBDL. Effects of ET-1 on intralobar pulmonary vascular segment reactivity and on eNOS expression and activity in rat pulmonary microvascular endothelial cells (RPMVECs) were also evaluated. Hepatic and plasma ET-1 levels increased 1 week after CBDL in association with a subsequent increase in pulmonary microvascular eNOS and ETB receptor levels and the onset of HPS. Selective ETB receptor inhibition in vivo significantly decreased pulmonary eNOS and ETB receptor levels and ameliorated HPS. CBDL pulmonary artery segments had markedly increased ETB receptor mediated, nitric oxide dependent vasodilatory responses to ET-1 compared with controls and ET-1 triggered an ETB receptor dependent stimulation of eNOS in RPMVECs. Pulmonary intravascular macrophages also accumulated after CBDL and expressed HO-1 and iNOS at 3 weeks. Selective ETB receptor blockade also decreased macrophage accumulation and iNOS production. In conclusion, ET-1 plays a central role in modulating pulmonary micovascular tone in experimental HPS. (HEPATOLOGY 2004;39:1593,1602.) [source] Left ventricular hypertrophy in rats with biliary cirrhosisHEPATOLOGY, Issue 3 2003Javier Inserte Portal hypertension induces neuroendocrine activation and a hyperkinetic circulation state. This study investigated the consequences of portal hypertension on heart structure and function. Intrahepatic portal hypertension was induced in male Sprague-Dawley rats by chronic bile duct ligation (CBDL). Six weeks later, CBDL rats showed higher plasma angiotensin-II and endothelin-1 (P < .01), 56% reduction in peripheral resistance and 73% reduction in pulmonary resistance (P < .01), 87% increase in cardiac index and 30% increase in heart weight (P < .01), and increased myocardial nitric oxide (NO) synthesis. In CBDL rats, macroscopic analysis demonstrated a 30% (P < .01) increase in cross-sectional area of the left ventricular (LV) wall without changes in the LV cavity or in the right ventricle (RV). Histomorphometric analysis revealed increased cell width (12%, P < .01) of cardiomyocytes from the LV of CBDL rats, but no differences in myocardial collagen content. Myocytes isolated from the LV were wider (12%) and longer (8%) than right ventricular myocytes (P < .01) in CBDL rats but not in controls. CBDL rats showed an increased expression of ANF and CK-B genes (P < .01). Isolated perfused CBDL hearts showed pressure/end-diastolic pressure curves and response to isoproterenol identical to sham hearts, although generated wall tension was reduced because of the increased wall thickness. Coronary resistance was markedly reduced. This reduction was abolished by inhibition of NO synthesis with N -nitro-L-arginine. Expression of eNOS was increased in CBDL hearts. In conclusion, portal hypertension associated to biliary cirrhosis induces marked LV hypertrophy and increased myocardial NO synthesis without detectable fibrosis or functional impairment. This observation could be relevant to patients with cirrhosis. [source] Activation of eNOS in rat portal hypertensive gastric mucosa is mediated by TNF-, via the PI 3-kinase,Akt signaling pathwayHEPATOLOGY, Issue 2 2002Hirofumi Kawanaka Activation of endothelial nitric oxide synthase (eNOS) in portal hypertensive (PHT) gastric mucosa leads to hyperdynamic circulation and increased susceptibility to injury. However, the signaling mechanisms for eNOS activation in PHT gastric mucosa and the role of TNF-, in this signaling remain unknown. In PHT gastric mucosa we studied (1) eNOS phosphorylation (at serine 1177) required for its activation; (2) association of the phosphatidylinositol 3-kinase (PI 3-kinase), and its downstream effector Akt, with eNOS; and, (3) whether TNF-, neutralization affects eNOS phosphorylation and PI 3-kinase,Akt activation. To determine human relevance, we used human microvascular endothelial cells to examine directly whether TNF-, stimulates eNOS phosphorylation via PI 3-kinase. PHT gastric mucosa has significantly increased (1) eNOS phosphorylation at serine 1177 by 90% (P < .01); (2) membrane translocation (P < .05) and phosphorylation (P < .05) of p85 (regulatory subunit of PI 3-kinase) by 61% and 85%, respectively; (3) phosphorylation (P < .01) and activity (P < .01) of Akt by 40% and 52%, respectively; and (4) binding of Akt to eNOS by as much as 410% (P < .001). Neutralizing anti,TNF-, antibody significantly reduced p85 phosphorylation, phosphorylation and activity of Akt, and eNOS phosphorylation in PHT gastric mucosa to normal levels. Furthermore, TNF-, stimulated eNOS phosphorylation in human microvascular endothelial cells. In conclusion, these findings show that in PHT gastric mucosa, TNF-, stimulates eNOS phosphorylation at serine 1177 (required for its activation) via the PI 3-kinase,Akt signal transduction pathway. [source] An intron 4 VNTR polymorphism of the endothelial nitric oxide synthase gene is associated with early-onset colorectal cancerINTERNATIONAL JOURNAL OF CANCER, Issue 7 2009Chih-Ching Yeh Abstract Endothelial-derived nitric oxide, which is produced by endothelial nitric oxide synthase (eNOS), may play an important role in colorectal carcinogenesis. However, the putative contribution of common eNOS genetic polymorphisms to colorectal cancer risk remains unknown. We genotyped 3 polymorphisms of eNOS (T-786C, G894T, and intron4b/a) in 727 colorectal adenocarcinoma cases and 736 age- and sex-matched healthy controls in Taiwan. Genotypes of the T-786C and G894T polymorphisms were determined by fluorescence polarization assays and the 27-bp variable number of tandem repeat (VNTR) polymorphism in intron 4 (intron4b/a) was analyzed by PCR. Logistic regression was used to calculate odds ratios (ORs) and 95% confidence intervals (CIs). Among younger participants (,60 yrs), the intron4a variant genotype was associated with a significantly increased risk of colorectal cancer, compared with the intron4bb genotype (OR = 1.60, 95% CI = 1.04,2.46). In addition, those young individuals bearing a greater number of high-risk genotypes (OR > 1, i.e., CT+TT for T-786C, ba+aa for intron4b/a, and GG for G894T) of eNOS had a higher colorectal cancer risk (ptrend = 0.039). Compared with younger individuals without any putative high-risk genotypes, those with 3 high-risk genotypes had a significantly greater cancer risk (OR = 1.89, 95% CI = 1.04,3.43). Our results suggest that the eNOS intron4b/a polymorphism may contribute to early-onset colorectal cancer risk in the Taiwanese population. © 2008 Wiley-Liss, Inc. [source] Xanthine oxidase inhibitor allopurinol attenuates the development of diabetic cardiomyopathyJOURNAL OF CELLULAR AND MOLECULAR MEDICINE, Issue 8b 2009Mohanraj Rajesh Abstract In this study, we investigated the effect of the xanthine oxidase (XO) inhibitor, allopurinol (ALP), on cardiac dysfunction, oxidative-nitrosative stress, apoptosis, poly(ADP-ribose) polymerase (PARP) activity and fibrosis associated with diabetic cardiomyopathy in mice. Diabetes was induced in C57/BL6 mice by injection of streptozotocin. Control and diabetic animals were treated with ALP or placebo. Left ventricular systolic and diastolic functions were measured by pressure,volume system 10 weeks after established diabetes. Myocardial XO, p22phox, p40phox, p47phox, gp91phox, iNOS, eNOS mRNA and/or protein levels, ROS and nitrotyrosine (NT) formation, caspase3/7 and PARP activity, chromatin fragmentation and various markers of fibrosis (collagen-1, TGF-,, CTGF, fibronectin) were measured using molecular biology and biochemistry methods or immunohistochemistry. Diabetes was characterized by increased myocardial, liver and serum XO activity (but not expression), increased myocardial ROS generation, p22phox, p40phox, p47phox, p91phox mRNA expression, iNOS (but not eNOS) expression, NT generation, caspase 3/7 and PARP activity/expression, chromatin fragmentation and fibrosis (enhanced accumulation of collagen, TGF-,, CTGF and fibronectin), and declined systolic and diastolic myocardial performance. ALP attenuated the diabetes-induced increased myocardial, liver and serum XO activity, myocardial ROS, NT generation, iNOS expression, apoptosis, PARP activity and fibrosis, which were accompanied by improved systolic (measured by the evaluation of both load-dependent and independent indices of myocardial contractility) and diastolic performance of the hearts of treated diabetic animals. Thus, XO inhibition with ALP improves type 1 diabetes-induced cardiac dysfunction by decreasing oxidative/nitrosative stress and fibrosis, which may have important clinical implications for the treatment and prevention of diabetic cardiomyopathy and vascular dysfunction. [source] Sildenafil-mediated neovascularization and protection against myocardial ischaemia reperfusion injury in rats: role of VEGF/angiopoietin-1JOURNAL OF CELLULAR AND MOLECULAR MEDICINE, Issue 6b 2008Srikanth Koneru Abstract Sildenafil citrate (SC), a drug for erectile dysfunction, is now emerging as a cardiopulmonary drug. Our study aimed to determine a novel role of sildenafil on cardioprotection through stimulating angiogenesis during ischaemia (I) reperfusion (R) at both capillary and arteriolar levels and to examine the role of vascular endothelial growth factor (VEGF) and angiopoietin-1 (Ang-1) in this mechanistic effect. Rats were divided into: control sham (CS), sildenafil sham (SS), control + IR (CIR) and sildenafil + IR (SIR). Rats were given 0.7 mg/kg, (i.v) of SC or saline 30 min. before occlusion of left anterior descending artery followed by reperfusion (R). Sildenafil treatment increased capillary and arteriolar density followed by increased blood flow (2-fold) compared to control. Treatment with sildenafil demonstrated increased VEGF and Ang-1 mRNA after early reperfusion. PCR data were validated by Western blot analysis. Significant reduction in infarct size, cardiomyocyte and endothelial apoptosis were observed in SC-treated rats. Increased phosphorylation of Akt, eNOS and expression of anti-apoptotic protein Bcl-2, and thioredoxin, hemeoxygenase-1 were observed in SC-treated rats. Echocardiography demonstrated increased fractional shortening and ejection fraction following 45 days of reperfusion in the treatment group. Stress testing with dobutamine infusion and echocardiogram revealed increased contractile reserve in the treatment group. Our study demonstrated for the first time a strong additional therapeutic potential of sildenafil by up-regulating VEGF and Ang-1 system, probably by stimulating a cascade of events leading to neovascularization and conferring myocardial protection in in vivo I/R rat model. [source] Nitrotyrosinylation, remodeling and endothelial-myocyte uncoupling in iNOS, cystathionine beta synthase (CBS) knockouts and iNOS/CBS double knockout miceJOURNAL OF CELLULAR BIOCHEMISTRY, Issue 1 2009Soumi Kundu Abstract Increased levels of homocysteine (Hcy), recognized as hyperhomocysteinemia (HHcy), were associated with cardiovascular diseases. There was controversy regarding the detrimental versus cardio protective role of inducible nitric oxide synthase (iNOS) in ischemic heart disease. The aim of this study was to test the hypothesis that the Hcy generated nitrotyrosine by inducing the endothelial nitric oxide synthase, causing endothelial-myocyte (E-M) coupling. To differentiate the role of iNOS versus constitutive nitric oxide synthase (eNOS and nNOS) in Hcy-mediated nitrotyrosine generation and matrix remodeling in cardiac dysfunction, left ventricular (LV) tissue was analyzed from cystathionine beta synthase (CBS) heterozygote knockout, iNOS homozygote knockout, CBS,/+/iNOS,/, double knockout, and wild-type (WT) mice. The levels of nitrotyrosine, MMP-2 and -9 (zymographic analysis), and fibrosis (by trichrome stain) were measured. The endothelial-myocyte function was determined in cardiac rings. In CBS,/+ mice, homocysteine was elevated and in iNOS,/, mice, nitric oxide was significantly reduced. The nitrotyrosine and matrix metalloproteinase-9 (MMP-9) levels were elevated in double knockout and CBS,/+ as compared to WT mice. Although MMP-2 levels were similar in CBS,/+, iNOS,/,, and CBS,/+/iNOS,/,, the levels were three- to fourfold higher than WT. The levels of collagen were similar in CBS,/+ and iNOS,/,, but they were threefold higher than WT. Interesting, the levels of collagen increased sixfold in double knockouts, compared to WT, suggesting synergism between high Hcy and lack of iNOS. Left ventricular hypertrophy was exaggerated in the iNOS,/, and double knockout, and mildly increased in the CBS,/+, compared to WT mice. The endothelial-dependent relaxation was attenuated to the same extent in the CBS,/+ and iNOS,/,, compared to WT, but it was robustly blunted in double knockouts. The results concluded that homocysteine generated nitrotyrosine in the vicinity of endothelium, caused MMP activation and endothelium-myocyte uncoupling. The generation of nitrotyrosine was independent of iNOS. J. Cell. Biochem. 106: 119,126, 2009. © 2008 Wiley-Liss, Inc. [source] Different protective actions of losartan and tempol on the renal inflammatory response to acute sodium overloadJOURNAL OF CELLULAR PHYSIOLOGY, Issue 1 2010María I. Rosón The aim of this work was to study the role of local intrarenal angiotensin II (Ang II) and the oxidative stress in the up-regulation of pro-inflammatory cytokines expression observed in rats submitted to an acute sodium overload. Sprague,Dawley rats were infused for 2,h with isotonic saline solution (Control group) and with hypertonic saline solution alone (Na group), plus the AT1 receptor antagonist losartan (10,mg,kg,1 in bolus) (Na,Los group), or plus the superoxide dismutase mimetic tempol (0.5,mg,min,1,kg,1) (Na,Temp group). Mean arterial pressure, glomerular filtration rate, and fractional sodium excretion (FENa) were measured. Ang II, NF-,B, hypoxia inducible factor-1, (HIF-1,), transforming growth factor ,1 (TGF-,1), smooth muscle actin (,-SMA), endothelial nitric oxide synthase (eNOS), and RANTES renal expression was evaluated by immunohistochemistry. Ang II, NF-,B, and TGF-,1 and RANTES early inflammatory markers were overexpressed in Na group, accompanied by enhanced HIF-1, immunostaining, lower eNOS expression, and unmodified ,-SMA. Losartan and tempol increased FENa in sodium overload group. Although losartan reduced Ang II and NF-,B staining and increased eNOS expression, it did not restore HIF-1, expression and did not prevent inflammation. Conversely, tempol increased eNOS and natriuresis, restored HIF-1, expression, and prevented inflammation. Early inflammatory markers observed in rats with acute sodium overload is associated with the imbalance between HIF-1, and eNOS expression. While both losartan and tempol increased natriuresis and eNOS expression, only tempol was effective in restoring HIF-1, expression and down-regulating TGF-,1 and RANTES expression. The protective role of tempol, but not of losartan, in the inflammatory response may be associated with its greater antioxidant effects. J. Cell. Physiol. 224:41,48, 2010 © 2010 Wiley-Liss, Inc. [source] LDL lipid apheresis rapidly increases peripheral endothelial progenitor cell competenceJOURNAL OF CLINICAL APHERESIS, Issue 5 2009Daniel Patschan Abstract Background and Aim: Endothelial progenitor cells (EPCs) have been shown to promote neovascularization under physiologic and pathologic conditions. Statins have been documented to increase the total number of circulating EPCs in long-term treated patients. Lipid apheresis is used to treat patient with refractory hyperlipidemia. The aim of our study was to evaluate whether lipid apheresis is associated with EPC mobilization. Methods: Thirteen patients with refractory hyperlipidemia (analysis at the beginning and at the end of a single lipid apheresis treatment) and 10 healthy controls were included into the study. For quantifying total peripheral EPCs, CD133+/Flk-1+ myelo-monocytic blood cells were enumerated by flow cytometry. The proliferative potential of EPCs was evaluated by a "colony-forming unit" assay. In some patients, EPC eNOS expression was evaluated before and after treatment. Results: Circulating EPCs and the cells' proliferative activity were lower in hyperlipidemia patients as compared to controls (0.14 ± 0.07 vs. 0.6 ± 0.14, P = 0.01, and 13.9 ± 4.9 vs. 45.6 ± 8.1, P = 0.0007). Lipid apheresis treatment was not associated with an increase in total EPCs. The cells' proliferative activity was strongly stimulated by lipid apheresis as reflected by an increase in the number of EPC colonies (13.9 ± 4.9 to 34.1 ± 7.3, P = 0.035). Analysis of EPC eNOS expression revealed a threefold increase in the cellular expression intensity after lipid apheresis. Conclusions: Patients with refractory hyperlipidemia exhibit lower peripheral EPC numbers and a lower proliferative activity of circulating EPCs than healthy controls. A single lipid apheresis treatment significantly stimulates EPC proliferation, it furthermore increases cellular eNOS. In summary, these results show that lipid apheresis mediates beneficial effects on the EPC system as an essential element in the process of vascular repair in the human organism. J. Clin. Apheresis 2009. © 2009 Wiley-Liss, Inc. [source] Endothelial NOS G894 T and MMP-3 5A/6A gene polymorphisms and hypertension in Serbian populationJOURNAL OF CLINICAL LABORATORY ANALYSIS, Issue 6 2005Tamara Djuri Abstract The incidence of hypertension is increasing and it is more common in man than in women. Up to date, MMP-3 5A/6A polymorphism has been associated with artery stiffening and elevated blood pressure, whereas results considering association of endothelial NOS (eNOS) G894 T polymorphism with hypertension are controversial. The aim of our study was to analyze the possible association of eNOS G894 T and MMP-3 5A/6A gene polymorphisms with hypertension in Serbian population. Study sample consisted of 172 hypertensive and 200 normotensive subjects divided by gender. Both female and male group was truncated according to age. All subjects were genotyped for MMP-3 5A/6A and eNOS G894 T polymorphism. There was a significantly higher (P < 0.05) prevalence of 5A/5A genotype in hypertensive females compared to normotensive ones (19.30 % vs. 10.84%) even more pronounced in group ,50 years, according to its recessive effect. In young males (<40 years), we found 3.7-fold increased risk for hypertension associated with allele 6A (P < 0.01), and 8.1-fold with genotype 6A/6A (P = 0.01) according to recessive model. We found no association of eNOS G894 T polymorphism with hypertension. These results indicate that there were gender- and age-specific differences in association of MMP-3 5A/6A polymorphism with hypertension in Serbian population. J. Clin. Lab. Anal. 19:214,246, 2005. © 2005 Wiley-Liss, Inc. [source] AMP-activated protein kinase deficiency exacerbates aging-induced myocardial contractile dysfunctionAGING CELL, Issue 4 2010Subat Turdi Summary Aging is associated with myocardial dysfunction although the underlying mechanism is unclear. AMPK, a key cellular fuel sensor for energy metabolism, is compromised with aging. This study examined the role of AMPK deficiency in aging-associated myocardial dysfunction. Young or old wild-type (WT) and transgenic mice with overexpression of a mutant AMPK ,2 subunit (kinase dead, KD) were used. AMPK , isoform activity, myocardial function and morphology were examined. DCF and JC-1 fluorescence probes were employed to quantify reactive oxygen species (ROS) and mitochondrial membrane potential (,,m), respectively. KD mice displayed significantly reduced ,2 but not ,1 AMPK isoform activity at both ages with a greater effect at old age. Aging itself decreased ,1 isoform activity. Cardiomyocyte contractile function, intracellular Ca2+ handling, and SERCA2a levels were compromised with aging, the effects of which were exacerbated by AMPK deficiency. H&E staining revealed cardiomyocyte hypertrophy with aging, which was more pronounced in KD mice. TEM micrographs displayed severe disruption of mitochondrial ultrastructure characterized by swollen, irregular shape and disrupted cristae in aged KD compared with WT mice. Aging enhanced ROS production and reduced ,,m, the effects of which were accentuated by AMPK deficiency. Immunoblotting data depicted unchanged Akt phosphorylation and a significant decrease in mitochondrial biogenesis cofactor PGC-1, in aged groups. AMPK deficiency but not aging decreased the phosphorylation of ACC and eNOS. Expression of membrane Glut4 and HSP90 was decreased in aged KD mice. Moreover, treatment of the AMPK activator metformin attenuated aging-induced cardiomyocyte contractile defects. Collectively, our data suggest a role for AMPK deficiency in aging-induced cardiac dysfunction possibly through disrupted mitochondrial function and ROS production. [source] Simvastatin effects on portal-systemic collaterals of portal hypertensive ratsJOURNAL OF GASTROENTEROLOGY AND HEPATOLOGY, Issue 8 2010Hui-Chun Huang Abstract Background and Aim:, Portal-systemic collateral vascular resistance and vasoconstrictor responsiveness are crucial in portal hypertension and variceal bleeding control. Statins enhance vasodilators production, but their influence on collaterals is unknown. This study aimed to survey the effect of simvastatin on collaterals. Methods:, Partially portal vein-ligated rats received oral simvastatin (20 mg/kg/day) or distilled water from ,2 to +7 day of ligation. After hemodynamic measurements on the eighth postoperative day, baseline perfusion pressure (i.e. an index of collateral vascular resistance) and arginine vasopressin (AVP, 0.1 nM,0.1 µM) responsiveness were evaluated with an in situ perfusion model for collateral vascular beds. RT-PCR of endothelial NO synthase (eNOS), inducible NOS (iNOS), cyclooxygenase-1 (COX-1), COX-2, thromboxane A2 synthase (TXA2 -S) and prostacyclin synthase genes was performed in parallel groups for splenorenal shunt (SRS), the most prominent intra-abdominal collateral vessel. To determine the acute effects of simvastatin, collateral AVP response was assessed with vehicle or simvastatin. SRS RT-PCR of eNOS, iNOS, COX-1, COX-2 and TXA2 -S, and measurements of perfusate nitrite/nitrate, 6-keto-PGF1, and TXB2 levels were performed in parallel groups without AVP. Results:, Acute simvastatin administration enhanced SRS eNOS expression and elevated perfusate nitrite/nitrate and 6-keto-PGF1, concentrations. Chronic simvastatin treatment reduced baseline collateral vascular resistance and portal pressure and enhanced SRS eNOS, COX-2 and TXA2 -S mRNA expression. Neither acute nor chronic simvastatin administration influenced collateral AVP responsiveness. Conclusion:, Simvastatin reduces portal-systemic collateral vascular resistance and portal pressure in portal hypertensive rats. This may be related to the enhanced portal-systemic collateral vascular NO and prostacyclin activities. [source] Site-specific detection of S -nitrosylated PKB ,/Akt1 from rat soleus muscle using CapLC-Q-TOFmicro mass spectrometryJOURNAL OF MASS SPECTROMETRY (INCORP BIOLOGICAL MASS SPECTROMETRY), Issue 9 2005Xiao-Ming Lu Abstract Protein Kinase B,(PKB,, or Akt1) is believed to play a crucial role in programmed cell death, cancer progression and the insulin-signaling cascade. The protein is activated by phosphorylation at multiple sites and subsequently phosphorylates and activates eNOS. Free cysteine residues of the protein may capture reactive, endogenously produced nitric oxide (NO) as S -nitrosothiols. Site-specific detection of S -nitrosylated cysteine residues, usually at low stoichiometry, has been a major challenge in proteomic research largely due to the lack of mass marker for S -nitrosothiols that are very labile under physiologic conditions. In this report we describe a sensitive and specific MS method for detection of S -nitrosothiols in PKB ,/Akt1 in rat soleus muscle. PKB ,/Akt1 was isolated by immunoprecipitation and 2D-gel electrophoresis, subjected to in-gel tryptic digestion, and cysteinyl nitrosothiols were reacted with iodoacetic acids [2-C12/C13 = 50/50] under ascorbate reduction conditions. This resulted in the production of relatively stable carboxymethylcysteine (CMC) immonium ions (m/z 134.019 and m/z 135.019) within a narrow argon collision energy (CE = 30 ± 5 V) in the high MS noise region. In addition, free and disulfide-linked cysteine residues were converted to carboxyamidomethylcysteines (CAM). Tryptic S -nitrosylated parent ion was detected with a mass accuracy of 50 mDa for the two CMC immonium ions at the triggered elution time during capillary liquid chromatography (LC) separation. A peptide containing Cys296 was discriminated from four co-eluting tryptic peptides under lock mass conditions (m/z 785.8426). S -nitrosothiol in the tryptic peptide, ITDFGLBKEGIK (B: CAM, [M + 2H]2+ = 690.86, Found: 690.83), is believed to be present at a very low level, since the threshold for the CMC immonium trigger ions was set at 3 counts/s in the MS survey. The high levels of NO that are produced under stress conditions may result in increased S -nitrosylation of Cys296 which blocks disulfide bond formation between Cys296 and Cys310 and suppresses the biological effects of PKB ,/Akt1. With the procedures developed here, this process can be studied under physiological and pathological conditions. Copyright © 2005 John Wiley & Sons, Ltd. [source] Hypoxic damage to the periventricular white matter in neonatal brain: role of vascular endothelial growth factor, nitric oxide and excitotoxicityJOURNAL OF NEUROCHEMISTRY, Issue 4 2006Charanjit Kaur Abstract The present study examined factors that may be involved in the development of hypoxic periventricular white matter damage in the neonatal brain. Wistar rats (1-day old) were subjected to hypoxia and the periventricular white matter (corpus callosum) was examined for the mRNA and protein expression of hypoxia-inducible factor-1, (HIF-1,), endothelial, neuronal and inducible nitric oxide synthase (eNOS, nNOS and iNOS), vascular endothelial growth factor (VEGF) and N-methyl-D-aspartate receptor subunit 1 (NMDAR1) between 3 h and 14 days after hypoxic exposure by real-time RT-PCR, western blotting and immunohistochemistry. Up-regulated mRNA and protein expression of HIF-1,, VEGF, NMDAR1, eNOS, nNOS and iNOS in corpus callosum was observed in response to hypoxia. NMDAR1 and iNOS expression was found in the activated microglial cells, whereas VEGF was localized to astrocytes. An enzyme immunoassay showed that the VEGF concentration in corpus callosum was significantly higher up to 7 days after hypoxic exposure. NO levels, measured by colorimetric assay, were also significantly higher in hypoxic rats up to 14 days after hypoxic exposure as compared with the controls. A large number of axons undergoing degeneration were observed between 3 h and 7 days after the hypoxic exposure at electron-microscopic level. Our findings point towards the involvement of excitotoxicity, VEGF and NO in periventricular white matter damage in response to hypoxia. [source] Poster Sessions CP08: Signal TransductionJOURNAL OF NEUROCHEMISTRY, Issue 2002G. Taglialatela Inducible nitric oxide synthase (iNOS) and high levels of nitric oxide (NO) are present in the CNS of patients with Alzheimer's disease (AD), resulting in both DNA and protein oxidative damage. While iNOS can result in damaging levels of NO, the neuronal constitutive form of NOS (nNOS) has a role in cell signalling and can prevent neuronal apoptosis. iNOS can be induced by inflammatory cytokines such as tumor necrosis alpha (TNF,). TNF, is found in the CNS of AD, where neurons dependent on neurotrophins such as nerve growth factor (NGF) are particularly affected. Here we determined the effect of TNF, on the three NOS isoforms (endothelial, neuronal and inducible) in NGF-responsive PC12 cells. We found that while TNF, and NGF alone were uneffective, their simultaneous addition resulted in iNOS induction and the release of NO. In addition TNF, and NGF synergistically reduced nNOS, independently of the presence of high NO levels promoted by iNOS, while no effect was observed on eNOS. A similar pattern was observed in the brain of aged human subjects as compared to young individuals. Our results suggest that synergistic iNOS induction by TNF, and NGF may occur in selective populations of NGF-responsive neurons. Oxidative damage in such neurons could then occur in the presence of elevated levels of TNF,, that potentially occur in the brain of AD patients. This damaging scenario may further be aggravated by a concomitant reduction of nNOS, brought about by similar synergistic effects between TNF, and NGF. Acknowledgements:, Supported by NIA (AG13945) and Sealy Res. Dev. grants to GT. [source] An angiotensin II type 1 receptor blocker can preserve endothelial function and attenuate brain ischemic damage in spontaneously hypertensive ratsJOURNAL OF NEUROSCIENCE RESEARCH, Issue 13 2010Naoki Oyama Abstract Hypertension reduces endothelial nitric oxide synthase (eNOS) expression and leads to endothelial dysfunction. However, few studies have demonstrated the influences of hypertension on eNOS function in the cerebral cortex. The present study investigates the influences of hypertension on endothelial function in the cerebral cortex and the protective effects of antihypertensive agents against brain ischemia through the preservation of endothelial function. Five- and ten-week-old male Wistar rats and spontaneously hypertensive rats (SHR) were used for experiments. Five-week-old SHR received olmesartan, hydralazine, or vehicle for 5 weeks in drinking water. eNOS activation in the cerebral cortex was evaluated by analyzing levels of total and Ser1177 -phosphorylated eNOS protein by Western blot. Blood pressure of 10-week-old SHR without treatment was clearly high, and the ratio of phospho-eNOS/total eNOS protein was significantly low. Five-week treatment with olmesartan or hydralazine suppressed the elevation of blood pressure and the reduction of phosphorylated eNOS-Ser1177 in SHR, and olmesartan was more effective in maintaining phosphorylation of eNOS-Ser1177 than hydralazine. To assess the contribution of eNOS to maintaining cerebral blood flow (CBF), we monitored CBF by laser-Doppler flowmetry after L-N5 -(1-iminoethyl)ornithine (L-NIO) infusion. CBF response to L-NIO was preserved in olmesartan-treated SHR but not in hydralazine-treated SHR. Furthermore, infarct volume 48 hr after transient focal brain ischemia in olmesartan-treated SHR was significantly reduced compared with vehicle-treated SHR. These findings indicate that chronic prehypertensive treatment with olmesartan could attenuate brain ischemic injury through the maintenance of endothelial function in the cerebral cortex in SHR. © 2010 Wiley-Liss, Inc. [source] Local isoform-specific NOS inhibition: A promising approach to promote motor function recovery after nerve injuryJOURNAL OF NEUROSCIENCE RESEARCH, Issue 9 2010Bernardo Moreno-López Abstract Physical injury to a nerve is the most frequent cause of acquired peripheral neuropathy, which is responsible for loss of motor, sensory and/or autonomic functions. Injured axons in the peripheral nervous system maintain the capacity to regenerate in adult mammals. However, after nerve transection, stumps of damaged nerves must be surgically joined to guide regenerating axons into the distal nerve stump. Even so, severe functional limitations persist after restorative surgery. Therefore, the identification of molecules that regulate degenerative and regenerative processes is indispensable in developing therapeutic tools to accelerate and improve functional recovery. Here, I consider the role of nitric oxide (NO) synthesized by the three major isoforms of NO synthases (NOS) in motor neuropathy. Neuronal NOS (nNOS) seems to be the primary source of NO that is detrimental to the survival of injured motoneurons. Endothelial NOS (eNOS) appears to be the major source of NO that interferes with axonal regrowth, at least soon after injury. Finally, NO derived from inducible NOS (iNOS) or nNOS is critical to the process of lipid breakdown for Wallerian degeneration and thereby benefits axonal regrowth. Specific inhibitors of these isoforms can be used to protect injured neurons from degeneration and promote axonal regeneration. A cautious proposal for the treatment of acquired motor neuropathy using therapeutic tools that locally interfere with eNOS/nNOS activities seems to merit consideration. © 2010 Wiley-Liss, Inc. [source] Estrogen administration during superovulation increases oocyte quality and expressions of vascular endothelial growth factor and nitric oxide synthase in the ovaryJOURNAL OF OBSTETRICS AND GYNAECOLOGY RESEARCH (ELECTRONIC), Issue 4 2010Choong-Sik Ha Abstract Aims:, This study investigated whether estrogen administration during superovulation enhances oocyte quality using a mice model. We also investigated whether this estrogen treatment regulates the expressions of angiogenic factors, such as vascular endothelial growth factor (VEGF) and endothelial nitric oxide synthase (eNOS), in the ovary. Method:, Female mice were co-injected with various doses of estrogen (1 µM, 10 µM and 100 µM) and pregnant mare serum gonadotrophin during superovulation, followed by human chorionic gonadotrophin injection 48 hours later. Then they were mated with individual males. After 18 hours, zygotes were flushed and cultured to blastocyst. The expression of VEGF and eNOS in the ovary was examined using Western blot and immunohistochemistry. The control group was superovulated without estrogen. Results:, Both numbers of ovulated zygotes and the rate of embryo development to blastocyst were significantly increased in the 1-µM estrogen dose compared to the control group. VEGF and eNOS expressions were stimulated by estrogen treatment. In particular, VEGF expression was significantly increased at 1-µM estrogen concentration, whereas, eNOS expression was significantly increased in all estrogen concentrations compared to controls. Conclusions:, The study showed that estrogen co-injection during superovulation increased the ovarian response, embryo developmental competence and expressions of VEGF and eNOS in the ovary. [source] Endothelial nitric oxide synthase gene polymorphisms in patients with nontraumatic femoral head osteonecrosisJOURNAL OF ORTHOPAEDIC RESEARCH, Issue 8 2006Kyung-Hoi Koo Abstract As endothelial nitric oxide synthase (eNOS) has beneficial effects on skeletal, vascular, and thrombotic systems, the association between nontraumatic femoral head osteonecrosis (FHON) and eNOS gene polymorphisms was investigated in Korean patients with FHON. Genomic DNA from 103 patients with nontraumatic FHON (idiopathic in 50, steroid-induced in 29, and alcohol abuse in 24) and 103 control subjects matched for gender and age (3-year range) was analyzed for the 27-bp repeat polymorphism in intron 4 and Glu298Asp polymorphism in exon 7. The frequencies of alleles and genotypes were compared between patients and control subjects. The frequency of 4a allele was significantly higher in total patients than control subjects [6.8% vs. 2.4%, p,=,0.0345, odds ratio (OR) 2.931]. In subgroup analysis, the 4a allele significantly increased in patients with idiopathic FHON versus control subjects (9.0% vs. 2.4%, p,=,0.0297, OR 3.976). The frequency of the 4a/b genotype in total patients (13.6% vs. 4.9%, p,=,0.0302, OR 3.083) as well as patients with idiopathic FHON (18.0% vs. 4.9%, p,=,0.0246, OR 4.302) was higher than control subjects. The distribution of Glu298Asp polymorphisms was not significantly different between patients and control subjects. Microstellate polymorphism in intron 4 of eNOS polymorphism was significantly associated with idiopathic FHON in Korean patients. Because 4a allele is associated with lower synthesis of eNOS, these results suggest that carrier state of 4a allele in intron 4 might be a genetic risk factor of FHON and could provide insight into the protective role of nitric oxide in the pathogenesis of FHON. © 2006 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 24:1722,1728, 2006 [source] Porphyromonas gingivalis stimulates the release of nitric oxide by inducing expression of inducible nitric oxide synthases and inhibiting endothelial nitric oxide synthasesJOURNAL OF PERIODONTAL RESEARCH, Issue 3 2010W. Sun Sun W, Wu J, Lin L, Huang Y, Chen Q, Ji Y. Porphyromonas gingivalis stimulates the release of nitric oxide by inducing expression of inducible nitric oxide synthases and inhibiting endothelial nitric oxide synthases. J Periodont Res 2010; 45: 381,388. © 2010 The Authors. Journal compilation © 2010 Blackwell Munksgaard Background and Objective:, The purpose of this study was to examine the ability of Porphyromonas gingivalis to invade human umbilical vein endothelial cells (HUVECs) and to study the effects of P. gingivalis ATCC 33277 on the production of nitric oxide (NO) and on the expression of inducible nitric oxide synthase (iNOS) and endothelial nitric oxide synthase (eNOS) in HUVECs. We attempted to throw light on the pathway of damage to endothelial function induced by P. gingivalis ATCC 33277. Material and Methods:,P. gingivalis ATCC 33277 was cultured anaerobically, and HUVECs were treated with P. gingivalis ATCC 33277 at multiplicities of infection of 1:10 or 1:100 for 4, 8, 12 and 24 h. HUVECs were observed using an inverted microscope and transmission electron microscopy. NO production was assayed through measuring the accumulation of nitrite in culture supernatants. Expression of both iNOS and eNOS proteins was investigated through western blotting. Results:, It was found that P. gingivalis ATCC 33277 can adhere to HUVECs by fimbriae, invade into HUVECs and exist in the cytoplasm and vacuoles. P. gingivalis ATCC 33277 can induce iNOS and inhibit eNOS expression, and stimulate the release of NO without any additional stimulant. Conclusion:, Our study provides evidence that P. gingivalis ATCC 33277 can invade HUVECs, and the ability of P. gingivalis ATCC 33277 to promote the production of NO may be important in endothelial dysfunction, suggesting that P. gingivalis ATCC 33277may be one of the pathogens responsible for atherosclerosis. [source] | |||||||||||||||||||||||||||||||||||||