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Fasting State (fasting + state)
Selected AbstractsIndirect evidence for increased mechanosensitivity of jejunal secretomotor neurones in patients with idiopathic bile acid malabsorptionACTA PHYSIOLOGICA, Issue 2 2009A. Bajor Abstract Aim:, The interdigestive motor rhythm, the migrating motor complex (MMC), is accompanied by active secretion of chloride during periods of distally propagating maximal motor activity (MMC phase III). We studied the behaviour of this system in bile acid malabsorption (BAM), a relative common cause of chronic diarrhoea. We measured motor activity and transmucosal potential difference (PD, reflecting active chloride secretion), in the proximal jejunum in healthy controls (n = 18) and in a group of patients with BAM (n = 11). The phase III-generated voltage was related to the degree of BAM quantified by the 75SeHCAT test. Methods:, We used a multi-channel intestinal infusion system to simultaneously measure jejunal pressure and PD. Saline passing calomel half-cells was infused into the jejunum and subcutaneously. Pressure and PD were recorded in the fasting state and after a test meal. Results:, In the absence of motor activity, jejunal PD was not significantly different from zero in either group. During MMC phase III, PD reached significantly higher mean and peak levels in BAM patients. The product of MMC phase III length multiplied by voltage, over 3 h, was also significantly higher in BAM patients (controls: median 307 mV × cm, range 70,398; BAM: median 511, range 274,2271, P < 0.01). This value was also significantly correlated with the degree of BAM as reflected by the 75SeHCAT test (P < 0.05). Conclusion:, Phase III induced jejunal secretion may be upregulated in BAM patients, resulting in overload of colonic reabsorption capacity. [source] Reduced insulin secretion in normoglycaemic patients with ,-thalassaemia majorDIABETIC MEDICINE, Issue 12 2006N. G. Angelopoulos Abstract Aims To assess insulin sensitivity and secretion in the fasting state in regularly transfused patients with ,-thalassaemia major with normal glucose response during an oral glucose tolerance test and to estimate its possible relation to iron overload. Methods We measured fasting glucose, insulin and C-peptide levels in 24 patients with ,-thalassaemia major and 18 control subjects matched for age and body mass index. Insulin sensitivity and insulin release index were calculated according to the homeostasis model assessment (HOMA). Correlations with age, body mass index and serum ferritin were also calculated. Results Fasting glucose levels in patients were increased compared with control subjects (5.5 ± 0.12 vs. 4.7 ± 0.13 mmol/l, mean ± sem, P < 0.001). Pancreatic B-cell insulin secretion in the fasting state (estimated by SCHOMA) was lower in thalassaemic patients (SCHOMA 88.5 ± 11.11 vs. 184.3 ± 23.72 in control subjects, P < 0.001). Patients were then divided into those with impaired (IFG) and normal (NFG) fasting glucose. SCHOMA was higher in the patients with NFG compared with those with IFG patients (110.6 ± 17.63 vs. 66.3 ± 10.88, respectively, P < 0.05) but estimated insulin sensitivity (ISIHOMA) was similar. Plasma values of C-peptide correlated positively with ferritin (r = 0.42, P = 0.04) and SCHOMA (r = 0.45, P = 0.02) and negatively with ISIHOMA (r = ,0.43, P = 0.03). Conclusions These results support the concept that impaired B-cell function, as reflected by a reduction in the insulin secretion index, is present in ,-thalassaemic patients with normoglycaemia before changes in oral glucose tolerance tests are apparent. [source] Prevalence and determinants of diabetes mellitus and glucose intolerance in a Canarian Caucasian population , comparison of the 1997 ADA and the 1985 WHO criteria.DIABETIC MEDICINE, Issue 3 2001The Guía Study. Summary Aims To estimate the prevalence of diabetes mellitus, impaired fasting glucose and impaired glucose tolerance in a Canarian population according to the 1997 ADA and the 1985 WHO criteria; and to study the cardiovascular risk factors associated with these categories. Methods A total of 691 subjects over 30 years old were chosen in a random sampling of the population (stratified by age and sex). An oral glucose tolerance test was performed (excluding known diabetic patients) and lipids were determined in the fasting state. Anthropometric and blood pressure measurements were performed, and history of smoking habits and medications was recorded. Results The prevalence of diabetes was 15.9% (1997 ADA) and 18.7% (1985 WHO); the prevalence of impaired fasting glucose and impaired glucose tolerance was 8.8 and 17.1%, respectively. The age-adjusted prevalence of diabetes (Segi's standard world population) for the population aged 30,64 years was 12.4% (1985 WHO). The risk factors significantly associated with diabetes (1997 ADA and 1985 WHO) were age, body mass index; waist-to-hip ratio, systolic and mean blood pressure, triglycerides, total cholesterol and low HDL-cholesterol. Age, body mass index and systolic blood pressure were associated with impaired fasting glucose and impaired glucose tolerance; triglycerides were also associated with impaired fasting glucose. Conclusions The prevalence of diabetes mellitus and glucose intolerance in Guía is one of the highest among studied Caucasian populations. The new 1997 ADA criteria estimate a lower prevalence of diabetes. Impaired fasting glucose also had a lower prevalence than impaired glucose intolerance and the overlap of these categories was modest. [source] Relevance of post-methionine homocysteine and lipoprotein (a) in evaluating the cardiovascular risk in young CAD patientsEUROPEAN JOURNAL OF CLINICAL INVESTIGATION, Issue 1 2005R. Marcucci Abstract Background, Aims of our study were to evaluate the prevalence of high lipoprotein (a) [Lp(a)] and homocysteine levels , both in the fasting state (FHcy) and post-methionine (PMHcy) , in young coronary artery disease (CAD) patients, and to investigate the role of genetic and environmental factors for hyperhomocysteinaemia. Materials and methods, We studied 140 patients with angiographically documented CAD (24 women , 55 years and 116 men , 50 years) and 140 healthy subjects as controls. Results, Both FHcy [13·2 (5·4,45·8) vs. 9·0 (5·1,24) µmol L,1); P < 0·0001] and PMHcy [(39·4 (9·0,66·4) vs. 25·2 (16·4,33·9); P < 0·0001] were significantly higher in patients than in controls. Lp(a) levels were significantly higher in patients than in controls (200 (3,1486) mg L,1 vs. 97 (10,412) mg L,1; P < 0·0001). At the multivariate analysis, adjusted for the classical cardiovascular risk factors and creatinine levels, the OR (95% CI) for CAD at young age significantly increased in the fourth quartile of the distribution of FHcy, PMHcy and Lp(a) levels [FHcy: 14·9 (4·1,58), P < 0·0001; PMHcy: 19·2 (4·0,86·3); P < 0·0001; Lp(a): 19·6 (4·7,78·6): < 0·0001]. Vitamin deficiencies were detected in 28/140 (20%) patients. The prevalence of the homozygous C677T (+/+) methylenetetrahydrofolatereductase genotype was higher, but not significantly different, in patients (22·8%) than in controls (18·6%). The allele frequency of the 844ins68 insertion variant in the cystathionine beta-synthase gene was 0·08 in the control group and 0·06 in the patient group. Conclusions, Results of the present study indicate the usefulness of including fasting and post-methionine Hcy, and Lp(a) determination in the diagnostic panels of young CAD patients, in order to obtain a better assessment of their cardiovascular risk profile. [source] Effects of audio stimulation on gastric myoelectrical activity and sympathovagal balance in healthy adolescents and adultsJOURNAL OF GASTROENTEROLOGY AND HEPATOLOGY, Issue 1 2008Dennis D Chen Abstract Aim:, The primary aim of this study was to investigate the effects of different audio stimulations on gastric myoelectrical activity and sympathovagal balance in adolescents compared with adults. Methods:, The study was performed in 11 adults and 12 adolescents. Each subject underwent two sessions, one for classical music, and the other for noise. Each session consisted of 30 min of baseline, 30 min of fasting audio stimulation, a test meal, 30 min of fed audio stimulation, and 30 min of recovery. Electrocardiogram and electrogastrogram were both recorded throughout each session. Results:, (i) In the fasting state, both classical music and noise impaired gastric slow wave activity in adolescents. In adults, noise had no effects while classical music moderately improved slow wave rhythmicity. (ii) In the fed state, neither noise nor music had any effects on gastric slow waves. (iii) In the fasting state, both noise and music increased the sympathovagal balance in adolescents; in adults only noise had such an effect. (iv) The test meal increased the sympathovagal balance in all groups. Conclusions:, Gastric slow waves and the sympathovagal balance are more strongly affected by audio stimulation in adolescents than in adults. The test meal normalizes the audio stimulation-induced differences between the groups. [source] Differential Effects of Restricted Versus Unlimited High-Fat Feeding in Rats on Fat Mass, Plasma Hormones and Brain Appetite RegulatorsJOURNAL OF NEUROENDOCRINOLOGY, Issue 7 2009T. Shiraev The rapid rise in obesity has been linked to altered food consumption patterns. There is increasing evidence that, in addition to total energy intake, the macronutrient composition of the diet may influence the development of obesity. The present study aimed to examine the impact of high dietary fat content, under both isocaloric and hypercaloric conditions, compared with a low fat diet, on adiposity, glucose and lipid metabolism, and brain appetite regulators in rats. Male Sprague,Dawley rats were exposed to one of three diets: control (14% fat), ad lib high-fat palatable (HFD, 35% fat) or high-fat palatable restricted (HFD-R, matched to the energy intake of control) and were killed in the fasting state 11 weeks later. Body weight was increased by 28% in unrestricted HFD fed rats, with an almost tripling of caloric intake and fat mass (P < 0.001) and double the plasma triglycerides of controls. Glucose intolerance and increased insulin levels were observed. HFD-R animals calorie matched to control had double their fat mass, plasma insulin and triglycerides (P < 0.05). Only ad lib consumption of the HFD increased the hypothalamic mRNA expression of the appetite-regulating peptides, neuropeptide Y and pro-opiomelanocortin. Although restricted consumption of palatable HFD had no significant impact on hypothalamic appetite regulators or body weight, it increased adiposity and circulating triglycerides, suggesting that the proportion of dietary fat, independent of caloric intake, affects fat deposition and the metabolic profile. [source] The influence of morphine on the absorption of paracetamol from various formulations in subjects in the supine position, as assessed by TDx measurement of salivary paracetamol concentrationsJOURNAL OF PHARMACY AND PHARMACOLOGY: AN INTERNATI ONAL JOURNAL OF PHARMACEUTICAL SCIENCE, Issue 10 2003Julia M. Kennedy ABSTRACT The aim of this study was to determine the influence of the type of paracetamol formulation on the rate of absorption when subjects are in the supine position, with or without taking concomitant morphine. Two groups of healthy volunteers were used, who were in the fasting state and remained in the supine position during the study. One group took 1500 mg of paracetamol on three occasions as conventional tablets, dispersible tablets or a suspension in a randomized crossover design. Seventeen saliva samples per subject were obtained (time zero to 360 min post-dose), which were then centrifuged and kept at ,20°C prior to analysis. The second group repeated the study following four doses of morphine syrup (10 mg 4 hourly) in the 12 h preceding paracetamol ingestion. In this phase of the study, paracetamol absorption from suspension was not investigated. A TDx assay was used to determine salivary paracetamol concentrations. The tmax for conventional tablets when taken concomitantly with morphine was 160 (+81) min compared to 51 (+58) min for subjects not taking morphine. For dispersible tablets the tmax in the morphine group was 14 (+9) min compared to 15 (+12) min without morphine. The results suggest that patients who are confined to bed and taking morphine will have an unacceptably long delay between taking conventional paracetamol tablets and the paracetamol reaching therapeutic plasma concentrations. Conversely, there is little effect on the absorption of dispersible paracetamol under the same conditions. [source] 12 Effects of synchronized intestinal electrical stimulation on small intestinal motility in dogsNEUROGASTROENTEROLOGY & MOTILITY, Issue 6 2006J YIN Our previous studies showed that synchronized gastric electrical stimulation enhanced antral contractions, accelerated gastric emptying in dogs. It has never been reported whether synchronized electrical stimulation could improve small intestinal motility. The aim of this study was to investigate the effects of synchronized intestinal electrical stimulation (SIES) on small bowel motility in both fasting and fed states in dogs. Methods:, Five healthy female dogs (18,24 kg) were equipped with a duodenal cannula for the measurement of small bowel motility using manometry. Two pairs of bipolar electrodes were implanted on the small intestinal serosa with an interval of 25 cm; the first one was 10 cm beyond the pylorus and used for stimulation. The experiment was consisted of four sessions in each dog with a randomized order. In the fasting state, 20 min after occurrence of phase III, SIES was initiated and maintained for 45 min, small bowel motility was recorded during the entire experiment, and no stimulation was performed in the control session. In other two sessions, dogs were fed with solid meal at the beginning of the experiment; glucagon (0.1 mg kg1) was injected 20 min after feeding, SIES was initiated at the same time for 20 min followed by 20 min recovery period. The stimulus was composed of train of pulses with on-time of 0.5 s, frequency of 20 Hz, pulse width of 2 ms and amplitude of 4 mA. Results:, 1). In the fasting state, SIES induced small intestinal contractions during phase I. The motility index was 5.2 ± 0.6 in the control session and significantly increased to 10.3 ± 0.7 with SIES (P = 0.003). 2). In the fed state, glucagon substantially and significantly inhibited small intestinal motility. The motility index was 11.3 ± 0.7 after feeding and reduced to 3.4 ± 0.5 with glucagon injection (P < 0.001). SIES significantly enhanced glucagon-induced small intestinal postprandial hypomotility. The motility index was 3.4 ± 0.5 in the control session and increased to 6.0 ± 0.3 with the presence of SIES (P = 0.03). Conclusions:, Intestinal electrical stimulation synchronized with intestinal slow waves induces intestinal contractions during phase I and enhanced small intestinal postprandial hypomotility induced by glucagon. SIES may have the therapeutic potential for treating small intestinal motility disorders. (Supported by a grant from American Diabetes Association). [source] 35 Electrogastrography in healthy participants: comparison of children and adultsNEUROGASTROENTEROLOGY & MOTILITY, Issue 6 2006CA FRIESEN The current study examined whether electrogastrogram (EGG) patterns differ between children/adolescents and adults, including whether EGG recordings obtained from healthy children would be considered normal by standards established for adults. Twenty-eight healthy children (54% females; ages 8,17, M = 12.4 years) were evaluated and compared to 15 healthy adults. EGGs were recorded for 30 min in the fasting state and for 1 h following a standard meal. For both pediatric and adult participants, there was a significant increase in both the dominant frequency and the dominant power from the pre- to the post , prandial period (p < 0.001 for each). There was a significant post-prandial increase in the %normal slow waves in pediatric participants only (81.5 vs. 89.0% vs. p < 0.001). Children demonstrated a significantly lower mean fasting %normal slow waves (81.5% vs. 94.2%) and a significantly greater fasting % tachygastria (8.9% vs. 2.3%) than did adults. Other parameters did not differ. Using adult standards, the %normal slow waves were ,70% of recording time in 96% children in the fasting state and in 100% in the postprandial period. A postprandial power increase was seen in 89% of the children. In conclusion, while adults should not be used as controls in pediatric studies of EGG, our data would indicate that American Motility Society (AMS) consensus adult criteria for a normal EGG are appropriate to apply to children and adolescents when utilizing methodology and meal challenge similar to that used to establish the adult norms. [source] 47 Effects of retrograde gastric electrical stimulation on gastric motility and plasma hormones in dogsNEUROGASTROENTEROLOGY & MOTILITY, Issue 6 2006G SONG Aims:, The aim of this study was to investigate the effect of different parameters of RGES with trains of long pulses in turning gastric slow waves into tachygastria, and evaluate the effects of RGES with the efficient trains of pulses on gastric slow waves, gastric emptying of solids and plasma concentrations of satiety-related peptides and glucose. Methods:, Seven female dogs implanted with four pairs of gastric electrodes were studied in two experiments. The first experiment included a series of sessions with different pacing parameters in the fasting state, each lasting 10 min. The second experiment included two randomized sessions (control and RGES). Gastric emptying of solid was measured by scintigraphy for a period of 4 h. Blood samples were collected at 45 and 15 min before, 30, 60 and 120 min after the meal. Plasma leptin, insulin and glucagon were measured using radioimmunoassay method. Plasma glucose was assessed with a commercially available glucometer. RGES was applied via the distal pair of electrodes (2 cm above the pylorus) with trains of pulses. RGES was initiated 30 min before the first blood sample and maintained for a period of 2.5 h. Gastric slow waves and symptomatic response were also recorded in each session. Results:, (1) RGES with pulse trains (12 trains/min) was able to turn regular gastric slow waves into tachygastria. (2) RGES with the efficient parameters (frequency: 40 Hz; pulse width: 2 ms; amplitude: 5 mA; train on-time, 2 s; off-time, 3 s) was capable of delaying gastric emptying of solids (P < 0.05). (3) Compared with the control session without RGES, the total AUC's of plasma insulin with RGES was significantly decreased in the fasting and postprandial periods (p < 0.05). However, the total area under curves (AUC's) of plasma leptin, glucagon, and glucose were not significantly affected by RGES (p > 0.05). (4) This method of GES induced no noticeable symptoms. Conclusion:, RGES with at a tachygastrial frequency decreases gastric emptying of solids and plasma insulin, but has no effects on plasma leptin, glucagons, and glucose. [source] Influence of maternal carbohydrate intake on fetal movements at 14 to 16 weeks of gestationPRENATAL DIAGNOSIS, Issue 2 2003Israel Goldstein Abstract Objective Ultrasonographic assessment of fetal movements at 14 to 16 weeks of gestation before and after maternal oral intake of carbohydrate. Design Thirty consecutive healthy pregnant women between 14 and 16 weeks of gestation were scanned transvaginally. Real-time ultrasound recordings of 20 min duration were performed in the fasting state and after an oral intake of 110 g of glucose. The number of fetal movements, body and limb movements and breathing movements were evaluated. Fetal movements were quantified using a digital chronometer, and the percentage of time spent moving and the rate of movements per minute were then calculated. Data was statistically analyzed using the simple and Wilcoxon paired t -test. Results Absolute number of fetal movements, body movements, rotation movements, time spent moving and rate of movements per minute showed a statistically significant increase after maternal intake of carbohydrate (p < 0.0001). Conclusions Maternal oral intake of 110 g of carbohydrate significantly increases fetal movements at 14 to 16 weeks of gestation, thus allowing better ultrasonographic viewing of the fetus. Copyright © 2003 John Wiley & Sons, Ltd. [source] An exploratory comparative study of volatile compounds in exhaled breath and emitted by skin using selected ion flow tube mass spectrometryRAPID COMMUNICATIONS IN MASS SPECTROMETRY, Issue 4 2008Claire Turner Selected ion flow tube mass spectrometry (SIFT-MS) has been used to carry out a pilot parallel study on five volunteers to determine changes occurring in several trace compounds present in exhaled breath and emitted from skin into a collection bag surrounding part of the arm, before and after ingesting 75,g of glucose in the fasting state. SIFT-MS enabled real-time quantification of ammonia, methanol, ethanol, propanol, formaldehyde, acetaldehyde, isoprene and acetone. Following glucose ingestion, blood glucose and trace compound levels were measured every 30,min for 2,h. All the above compounds, except formaldehyde, were detected at the expected levels in exhaled breath of all volunteers; all the above compounds, except isoprene, were detected in the collection bag. Ammonia, methanol and ethanol were present at lower levels in the bag than in the breath. The aldehydes were present at higher levels in the bag than in breath. The blood glucose increased to a peak about 1,h post-ingestion, but this change was not obviously correlated with temporal changes in any of the compounds in breath or emitted by skin, except for acetone. The decrease in breath acetone was closely mirrored by skin-emitted acetone in three volunteers. Breath and skin acetone also clearly change with blood glucose and further work may ultimately enable inferences to be drawn of the blood glucose concentration from skin or breath measurements in type 1 diabetes. Copyright © 2008 John Wiley & Sons, Ltd. [source] Bioavailability of modified-release methylphenidate: influence of high-fat breakfast when administered intact and when capsule content sprinkled on applesauceBIOPHARMACEUTICS AND DRUG DISPOSITION, Issue 6 2003Lucy Lee Abstract Ritalin®, an immediate release form of racemic methylphenidate hydrochloride, has been available in the USA since 1955 and is used for the treatment of ADHD. The objective of this study was to evaluate the pharmacokinetics of modified-release methylphenidate (highest single dose), Ritalin® LA, when administered under fasting condition, with a high-fat breakfast, and when sprinkled on applesauce in healthy adult subjects. Blood samples were drawn for 24 h following a 40 mg oral administration. Most subjects appeared to produce a bimodal methylphenidate plasma concentration profile. In all three treatment groups, methylphenidate was rapidly absorbed with an initial average tmax(0,4) of 1.3,2.4 h and an average peak plasma concentration [Cmax(abs)] of 14.4,15.2 ng/ml. On average, both the rate [Cmax(abs) and tmax(abs)] and the extent of absorption (AUC0,,) of methylphenidate were similar when the capsule was given with a high fat breakfast and when the capsule contents were sprinkled onto applesauce, compared with the fasting state. No dose dumping was observed when the capsule was given with a high fat breakfast or when sprinkled onto applesauce. The dose was safe and generally well tolerated. Coadministration of a single oral dose of 40 mg methylphenidate capsule whether administered intact with a high-fat breakfast or sprinkled on applesauce did not affect the overall rate or extent of absorption of methylphenidate compared with the fasted condition. Copyright © 2003 John Wiley & Sons, Ltd. [source] Pharmacokinetics and pharmacodynamics of TF-505, a novel nonsteroidal 5,-reductase inhibitor, in normal subjects treated with single or multiple dosesBRITISH JOURNAL OF CLINICAL PHARMACOLOGY, Issue 3 2002Tomoe Fujita Aims To assess the tolerability, pharmacokinetics and pharmacodynamics of a novel nonsteroidal,, and,, noncompetitive,, inhibitor,, of,, type,, I,, and,, type,, II,, 5,-reductases, (,)-(S)-4-[1-[4-[1-(4-isobutylphenyl) butoxy]benzoyl]indolizin-3-yl]butyric acid (TF-505), after single and multiple oral doses in healthy volunteers. Methods In the single-dose study, six young adult males in each dose group received 25 mg or 50 mg of TF-505, and six older males (, 40 years) in each dose group received 75 mg or 100 mg of TF-505. The subjects were given the drug in ascending dose and in the fasting state. Six subjects also received 50 mg of TF-505 after breakfast in a two-period crossover manner. In the multiple-dose study, six older males in each dose group received 12.5 mg or 25 mg TF-505 after breakfast daily for 7 days. Plasma concentrations of TF-505, dihydrotestosterone (DHT) and testosterone were measured. The pharmacokinetics of TF-505 were analysed by a compartment model with first-order absorption, first-order elimination and a lag time. Pharmacokinetic and pharmacodynamic relationships were evaluated by indirect response modelling with inhibition of input. Results Maximum plasma concentration (Cmax) and the area under the concentration,time curve (AUC) increased proportionately after the single dose up to 50 mg and with the multiple doses. Linearity was not detected between 75 and 100 mg of TF-505. Dose dependency was also noted for the effect of TF-505 on DHT concentrations following single doses up to 50 mg and multiple doses. Plasma DHT concentrations decreased maximally to 58.2, 49.5, 54.2 and 49.8% of basal values at 8,12 h after single administration of 25, 50, 75 and 100 mg TF-505, respectively, and to 60.5 and 49.4% at the 7th and 5th dose following multiple doses of 12.5 and 25 mg TF-505, respectively. The predicted effect curves matched the observed data when the indirect response model was applied to the time course of the suppressant effect of TF-505 on plasma DHT concentrations after both the single and multiple studies. Fifty percent inhibitory concentrations (IC50) of 0.82, 1.48, 1.31 and 0.88 µ g ml,1, zero-order rate constants for the onset of plasma DHT concentration changes (kin) of 17.8, 17.4, 17.0 and 10.7% h,1 and first-order rate constants,, for,, increase,, in,, plasma,, DHT,, concentrations,, to,, basal,, values,, (kout),, of,, 0.17,,, 0.16,,, 0.17,, and,, 0.10 h,1,, for,, the,, single,, study,, at,, doses,, of,, 25,,, 50,,, 75,, and 100 mg, respectively, were attained. In the multiple-dose study, IC50s were 1.74 and 1.49 µg ml,1 for the 12.5 and 25 mg doses, respectively. No serious adverse events related to TF-505 were observed. Conclusions TF-505 was well tolerated in healthy male volunteers. Accumulation of TF-505 in plasma was not observed during multiple dosing. The indirect response model described the relationships between pharmacokinetics and pharmacodynamics of TF-505. Such modelling is expected to yield an appropriate dosage regimen in subsequent clinical trials. [source] Circulating adiponectin levels during human endotoxaemiaCLINICAL & EXPERIMENTAL IMMUNOLOGY, Issue 1 2003P. KELLER SUMMARY Adiponectin, an adipocytokine secreted by fat tissue, may prevent development of diabetes type II, as high adiponectin levels are linked with insulin sensitivity. In contrast, tumour necrosis factor (TNF)- ,, which is also produced by fat tissue, leads to insulin resistance and furthermore inhibits adiponectin mRNA production and secretion of the protein. However, adiponectin also negatively regulates TNF- , levels. Therefore, we set out to test whether an infusion of endotoxin would influence circulating adiponectin levels in healthy human subjects. Twenty-three healthy human subjects were injected with endotoxin (2 ng/kg body weight); eight of these subjects were also injected with saline and served as controls. Plasma levels of adiponectin, TNF- , and interleukin-6 were measured at 0, 1·5, 2, 4, 8 and 24 h. TNF- , and interleukin-6 levels peaked at 1·5 h and 2 h, respectively. Control subjects injected with saline showed a decrease in adiponectin plasma levels with time (P < 0·05) presumably owing to the effect of fasting or physical inactivity. However, there was no change in adiponectin plasma levels in endotoxin injected subjects, thus the effect of fasting was opposed. In conclusion, circulating adiponectin levels are reduced during a resting and fasting state, an effect reversed by endotoxin injection. [source] Effects of a high-fat meal on resistance vessel reactivity and on indicators of oxidative stress in healthy volunteersCLINICAL PHYSIOLOGY AND FUNCTIONAL IMAGING, Issue 4 2001Andreas Schinkovitz High fat meals postprandially impair macrovascular endothelial function and a link to increased oxidative stress is suggested. Few information, on the other hand, exists on the effect of postprandial hyperlipidaemia on resistance vessel function. Under normal circumstances this vascular bed regulates tissue perfusion and, by controlling flow, impacts on macrovascular nitric oxide formation. The impact of a high fat meal (1200 kcal, 90 g fat, 46 g protein and 47 g carbohydrates) on postprandial resistance vessel reactivity and on indicators of oxidative stress was studied in 11 healthy subjects by venous-occlusion plethysmography using another six subjects as time control group. Ingestion of the test meal resulted in a pronounced increase of serum triglycerides from 1·05 ± 0·61 mmol l,1 in the fasting state to peak postprandial values of 1·94 ± 0·41 mmol l,1 (P < 0·001) reached after 4 h and a return to baseline after 8 h. Fasting peak reactive hyperaemia (RH) was 19·6 ± 2·4 ml min,1 (100 ml),1. Two hours after ingestion of the test meal peak RH was transiently reduced to 16·8 ± 2·2 ml min,1 (100 ml),1 (P < 0·05). No alteration of resting forearm perfusion was observed. The time course of peak RH suggested a potential biphasic effect of the test meal with an early impairment and a late increase of RH. Ingestion of a lipid rich test meal did not exert any influence on either total plasma antioxidant capacity given in trolox equivalents (513 ± 26 ,mol l,1 at baseline) or on plasma peroxides measured as H2O2 equivalents (469 ± 117 ,mol l,1). Our results suggest that ingestion of a meal containing 90 g of fat results in a transient impairment of reactive hyperaemia in healthy subjects but these vascular alterations are not accompanied by signs of systemically increased oxidative stress. [source] | |||||||||||||