Different responses of circulating ghrelin, obestatin levels to fasting, re-feeding and different food compositions, and their local expressions in rats

Obestatin, a sibling of ghrelin derived from preproghrelin, opposes several physiological actions of ghrelin. Our previous study has demonstrated that both plasma ghrelin and obestatin levels were decreased significantly 2h after food intake in human. To further expand current knowledge, we investigated the temporal profiles of their levels in ad libitum fed rats, 48h fasted rats and 48h fasted rats refed 2h with a standard chow, crude fiber, 50% glucose or water, and their expressions in stomach, liver and pancreatic islets immunohistochemically. Plasma ghrelin and obestatin levels were measured by EIA. Plasma leptin, insulin and glucose levels were also evaluated. Both plasma ghrelin and obestatin levels increased significantly in fasted rats compared with ad libitum fed rats. The ingestion of standard chow produced a profound and sustained suppression of ghrelin levels, whereas plasma obestatin levels decreased significantly but recovered quickly. Intake of crude fiber or 50% glucose, however, produced a more profound and sustained suppression of obestatin levels, though they had relatively less impact on ghrelin levels. Plasma glucose was the only independent predictor of ghrelin levels, obestatin levels, and ghrelin to obestatin ratios. Obestatin immunoreactivity was detected in the fundus of stomach, liver and pancreatic islets, with roughly similar patterns of distribution to ghrelin. These data show quantitative and qualitative differences in circulating ghrelin and obestatin responses to the short-term feeding status and nutrient composition, and may support a role for obestatin in regulating metabolism and energy homeostasis.     

Simultaneous decrease of plasma obestatin and ghrelin levels after a high-carbohydrate breakfast in healthy women

Ghrelin is a gut peptide produced mainly by stomach, well known to induce appetite stimulatory actions. Obestatin, a recently identified peptide derived from preproghrelin, was initially described to antagonize stimulatory effect of ghrelin on food intake. The postprandial response of obestatin and its relationship with ghrelin in humans remains unknown. We therefore investigated the postprandial response of obestatin and total ghrelin, acyl and desacyl ghrelin and neuropeptide Y (NPY) to a high-carbohydrate breakfast (1 604 kJ) in eight healthy women (age: 24.2+/-0.82 years; BMI 21.6+/-0.61 kg/m(2)). Blood samples were collected before the meal, and 30, 60, 90, 120 and 150 min after the breakfast consumption. Postprandial plasma obestatin concentrations significantly decreased compared with preprandial levels as well as total ghrelin concentrations and reached the lowest values 90 and 120 min after the meal consumption, respectively (p<0.05). Plasma acyl and desacyl ghrelin concentrations decreased after the breakfast and reached lowest values in 30 and 60 min, respectively (p<0.05). Plasma NPY concentrations were lower than preprandial levels 90 and 150 min after consuming breakfast (p<0.05). In conclusion, we demonstrated in healthy young women that plasma obestatin concentrations decrease similarly to ghrelin after a high-carbohydrate breakfast.     

Plasma obestatin levels in normal weight, obese and anorectic women

Obestatin is a recently discovered peptide produced in the stomach, which was originally described to suppress food intake and decrease body weight in experimental animals. We investigated fasting plasma obestatin levels in normal weight, obese and anorectic women and associations of plasma obestatin levels with anthropometric and hormonal parameters. Hormonal (obestatin, ghrelin, leptin, insulin) and anthropometric parameters and body composition were examined in 15 normal weight, 21 obese and 15 anorectic women. Fasting obestatin levels were significantly lower in obese than in normal weight and anorectic women, whereas ghrelin to obestatin ratio was increased in anorectic women. Compared to leptin, only minor differences in plasma obestatin levels were observed in women who greatly differed in the amount of fat stores. However, a negative correlation of fasting obestatin level with body fat indexes might suggest a certain role of obestatin in the regulation of energy homeostasis. A significant relationship between plasma obestatin and ghrelin levels, independent of anthropometric parameters, supports simultaneous secretion of both hormones from the common precursor. Lower plasma obestatin levels in obese women compared to normal weight and anorectic women as well as increased ghrelin to obestatin ratio in anorectic women might play a role in body weight regulation in these pathologies.     

Circulating Obestatin Levels Correlate with Fasting Insulin and HOMA-IR but Not with Hypertension in Elderly Men

Obestatin, encoded by the same gene as ghrelin, was first described as a physiological opponent of ghrelin. The association between circulating obestatin levels and blood pressure remains unclear. Furthermore, adequate information is non-existent regarding the older male population with hypertension. For this purpose, we enrolled 185 unrelated hypertensive male patients aged ≥80 years (range 80–102 years). One hundred seventy nine age-matched healthy subjects served as controls. Plasma levels of obestatin and insulin were measured using commercial ELISA and RIA. HOMA-IR was calculated using standard method. We found that plasma obestatin levels correlated significantly with insulin levels (P = 0.034) and homeostasis model assessment index for insulin resistance (HOMA-IR: P = 0.028). However, plasma obestatin differed non-significantly between hypertensive (5.06 ± 0.68 ng/mL) and non-hypertensive (4.72 ± 0.82 ng/mL) individuals. Plasma obestatin levels were not associated with systolic (P = 0.818) or diastolic (P = 0.564) blood pressure, waist-to-hip ratio (WHR: P = 0.725), uric acid (P = 0.603), total cholesterol (TC: P = 0.589), low-density lipoprotein cholesterol (LDL-C: P = 0.057); high-density lipoprotein cholesterol (HDL-C: P = 0.432), triglyceride (TG: P = 0.418), and fasting blood glucose (FBG: P = 0.101). We, therefore, concluded that fasting circulating obestatin levels did not directly correlate with blood pressure in men aged ≥80 years.     

Changes of plasma obestatin, ghrelin and NPY in anorexia and bulimia nervosa patients before and after a high-carbohydrate breakfast

Peptides ghrelin, obestatin and neuropeptide Y (NPY) play an important role in regulation of energy homeostasis, the imbalance of which is associated with eating disorders anorexia (AN) and bulimia nervosa (BN). The changes in ghrelin, obestatin and NPY plasma levels were investigated in AN and BN patients after administration of a high-carbohydrate breakfast (1604 kJ). Eight AN women (aged 25.4+/-1.9, BMI: 15.8+/-0.5), thirteen BN women (aged 22.0+/-1.05, BMI: 20.1+/-0.41) and eleven healthy women (aged 25.1+/-1.16, BMI: 20.9+/-0.40) were recruited for the study. We demonstrated increased fasting ghrelin in AN, but not in BN patients, while fasting obestatin and NPY were increased in both AN and BN patients compared to the controls. Administration of high-carbohydrate breakfast induced a similar relative decrease in ghrelin and obestatin plasma levels in all groups, while NPY remained increased in postprandial period in both patient groups. Ghrelin/obestatin ratio was lower in AN and BN compared to the controls. In conclusions, increased plasma levels of fasting NPY and its unchanged levels after breakfast indicate that NPY is an important marker of eating disorders AN and BN. Different fasting ghrelin and obestatin levels in AN and BN could demonstrate their diverse functions in appetite and eating suppression.     

Fenvalerate-induced chromosome aberrations and sister chromatid exchanges in the bone marrow cells of mice in vivo

To investigate whether subjects with low-acid states are exposed to increased genetic risk with respect to controls, we evaluated mutagenicity and presence of clastogenic factors (CF) in the gastric juice of chronic atrophic gastritis and omeprazole-treated patients. Mutagenic gastric juice was found in 8/15 (53%) chronic atrophic gastritis patients, 8/11 (73%) omeprazole-treated patients, and 2/13 (15%) healthy control subjects. The mean mutagenicity ratio of omeprazole-treated patients (1.52+/-0.48/0.1 ml gastric juice) was significantly higher than those of either controls (1.07+/-0.15; P<0.01) or chronic atrophic gastritis patients (1.16+/-0.21; P<0.05). Only chronic atrophic gastritis patients showed an increased clastogenic index with respect to healthy controls (2.67+/-2.13 versus 0.38+/-0.51; P<0.001). These findings expand our knowledge of gastric disease risk factors, and indicate that there may well be a risk of mucosal DNA damage arising from the presence of mutagenic and CF in the gastric juice.     

A single circuit-resistance exercise has no effect on plasma obestatin levels in female college students

Obestatin is a 23 amino acid peptide recently isolated from rat stomach that is encoded by the same gene as ghrelin. Obestatin has opposite action to ghrelin on food intake and plays a role in energy balance. The purpose of the present study was to investigate the effect of a circuit-resistance exercise (9 exercises, 25s per exercise, at 40, 60, 80% of 1RM) at different intensities on plasma obestatin and growth hormone (GH). Twenty volunteer females were randomly divided into four; 40, 60, 80%, combined (40+80+80%) loads groups (COL). Blood samples were collected before and immediately following the exercise protocol. Changes in plasma obestatin levels were not significant within and between groups. Plasma GH concentrations were significantly higher in high and COL groups, respectively. The data indicate that although circuit-resistance exercise resulted in a significant change in GH levels, it had no effect on plasma obestatin levels.     

Obestatin, acylated and total ghrelin concentrations in the perinatal rat pancreas

BACKGROUND: Ghrelin and obestatin are encoded by the preproghrelin gene and originate from posttranslational processing of the preproghrelin peptide. The fetal rat pancreas contains acylated and desacylated ghrelin peptides, as well as growth hormone secretagogue receptor -1a mRNA. Acylated ghrelin inhibits insulin secretion. We investigated the plasma and tissue ontogeny of ghrelin and obestatin in the rat. METHODS: We measured obestatin and acylated and total ghrelin concentrations in plasma, pancreas and stomach from rat fetuses (F20) and neonates at postnatal day (PN) 1, 6, 12 and 21). RESULTS: Overall, obestatin concentrations were markedly lower than total ghrelin concentrations. In plasma, total ghrelin concentrations decreased abruptly after birth (p < 0.05), contrasting with a 3 times increase in the concentration of acylated ghrelin between F20 and PN1 (p < 0.05). In pancreas, total ghrelin and obestatin concentrations decreased progressively from PN1 to PN21 but acylated ghrelin concentrations increased 6-7 times from F20 (18 [6] pg/ml) to PN6 (122 [59] pg/ml). The percent of acylated ghrelin increased from 1.8 (0.6) at F20 to 39.7 (13.0) % of total ghrelin immunoreactivity at PN12 (p < 0.05). There were significant positive correlations between postnatal obestatin, acylated or total ghrelin and insulin concentrations in the pancreas (all p < 0.02, r(2) > 0.21) and between postnatal total ghrelin and obestatin (in pancreas, r(2) = 0.37) or acylated ghrelin (in stomach, r(2) = 0.27) (p < 0.001). CONCLUSION: Ghrelin and obestatin are present in the perinatal pancreas where they could potentially affect insulin secretion.     

幽门螺杆菌感染与血浆obestatin水平的关系研究

目的：obestatin是新发现的与肥胖相关的多肽,本研究探讨幽门螺杆菌（H．pylori）对体重指数（BMI）~LM浆obestatin水平的影响。方法：于我院体检中心入选健康体检者205例,所有入选者无明确的胃肠疾病史,无心脏、肾脏、肝脏、甲状腺等疾病病史,无急性感染等其他可能影响激素水平的因素。幽门螺杆菌的感染依据l3C呼气实验及血清学指标联合判定。应用放射免疫分析法测定血浆obestatin及血清胰岛素水平。血清血脂水平采用自动生化分析仪进行酶法测定。胰岛素抵抗采用胰岛素抵抗指数（HOMA-IR）评定,HOMA—IR=空腹胰岛素（p~IU／ml）x空腹血糖（mmol／L）／22．5。结果：在我们的75例研究对象中H．pylori阳性的检出率为39％,幽门螺杆菌感染阳性者与阴性者相比,体重指数（BMI）差异并无统计学意义,血浆obestafin水平无显著性的差异。按体重指数进行分组,BMI〉24kg／m2组与BMI〈24kg／m2相比血浆obestatin水平明显下降。结论：H．pylori的感染状态并没有显著影响个体的循环obestatin水平。BMI对血浆obestatin水平有影响。     

EFFECT OF EXERCISE ON APPETITE-REGULATING HORMONES IN OVERWEIGHT WOMEN

Over the past decade, our knowledge of how homeostatic systems regulate food intake and body weight has increased with the discovery of circulating peptides such as leptin, acyl ghrelin, des-acyl ghrelin and obestatin. These hormones regulate the appetite and food intake by sending signals to the brain regarding the body''s nutritional status. The purpose of this study was to investigate the response of appetite-regulating hormones to exercise. Nine overweight women undertook two 2 h trials in a randomized crossover design. In the exercise trial, subjects ran for 60 min at 50% of maximal oxygen uptake followed by a 60 min rest period. In the control trial, subjects rested for 2 h. Obestatin, acyl ghrelin, des-acyl ghrelin and leptin concentrations were measured at baseline and at 20, 40, 60, 90 and 120 min after baseline. A two-way ANOVA revealed a significant (P < 0.05) interaction effect for leptin and acyl ghrelin. However, changes in obestatin and des-acyl ghrelin concentration were statistically insignificant (P > 0.05). The data indicated that although acute treadmill exercise resulted in a significant change in acyl ghrelin and leptin levels, it had no effect on plasma obestatin and des-acyl ghrelin levels.     

Proghrelin-derived peptides influence the secretion of insulin, glucagon, pancreatic polypeptide and somatostatin: a study on isolated islets from mouse and rat pancreas

Proghrelin, the precursor of the orexigenic and adipogenic peptide hormone ghrelin, is synthetized in endocrine (A-like) cells in the gastric mucosa. During its cellular processing, proghrelin gives rise to the 28-amino acid peptide desacyl ghrelin, which after octanoylation becomes active acyl ghrelin, and to the 23-amino acid peptide obestatin, claimed to be a physiological opponent of acyl ghrelin. This study examines the effects of the proghrelin products, alone and in combinations, on the secretion of insulin, glucagon, pancreatic polypeptide (PP) and somatostatin from isolated islets of mice and rats. Surprisingly, acyl ghrelin and obestatin had almost identical effects in that they stimulated the secretion of glucagon and inhibited that of PP and somatostatin from both mouse and rat islets. Obestatin inhibited insulin secretion more effectively than acyl ghrelin. In mouse islets, acyl ghrelin inhibited insulin secretion at low doses and stimulated at high. In rat islets, acyl ghrelin inhibited insulin secretion in a dose-dependent manner but the IC(50) for the acyl ghrelin-induced inhibition of insulin release was 7.5 x 10(-8) M, while the EC(50) and IC(50) values, with respect to stimulation of glucagon release and to inhibition of PP and somatostatin release, were in the 3 x 10(-12)-15 x 10(-12) M range. The corresponding EC(50) and IC(50) values for obestatin ranged from 5 x 10(-12) to 20 x 10(-12) M. Desacyl ghrelin per se did not affect islet hormone secretion. However, at a ten times higher concentration than acyl ghrelin (corresponding to the ratio of the two peptides in circulation), desacyl ghrelin abolished the effects of acyl ghrelin but not those of obestatin. Acyl ghrelin and obestatin affected the secretion of glucagon, PP and somatostatin at physiologically relevant concentrations; with obestatin this was the case also for insulin secretion. The combination of obestatin, acyl ghrelin and desacyl ghrelin in concentrations and proportions similar to those found in plasma resulted in effects that were indistinguishable from those induced by obestatin alone. From the data it seems that the effects of endogenous, circulating acyl ghrelin may be overshadowed by obestatin or blunted by desacyl ghrelin.     

Obestatin对血浆ghrelin和nesfatin-1水平及胃排空的影响

目的:探讨侧脑室注射obestatin对大鼠血浆酰基化ghrelin、去酰基化ghrelin、nesfatin-1水平的影响以及对胃排空的调控。方法:侧脑室注射obestatin,采用酶免疫测定(EIA)法检测血浆酰基化ghrelin、去酰基化ghrelin、nesfatin-1水平以及胃排空率的变化。结果:侧脑室分别注射0.1、0.3或1.0 nmol obestatin,大鼠血浆酰基化ghrelin、去酰基化ghrelin以及nesfatin-1水平无显著改变(P0.05),且酰基化ghrelin与去酰基化ghrelin比率无显著改变(P0.05);侧脑室注射obestatin,大鼠摄食量无显著改变,但胃排空率明显增加(P0.05);胃排空率明显延迟(P0.05)。与侧脑室注射1.0 nmol Obestatin组相比,注射1.0 nmol Obestatin+CRF,大鼠摄食量无显著改变,胃排空率明显延迟(P0.05)。各组摄食量及进入十二指肠内食物量无明显差异(P0.05)。结论:中枢obestatin促进大鼠的胃排空,可能与h/r CRF通路有关。     

Obestatin is present in saliva: alterations in obestatin and ghrelin levels of saliva and serum in ischemic heart disease

Ghrelin and obestatin are a single gene products and are a multiple functional peptides that regulates energy homeostasis, and food intake. In the present work, we studied the secretion of ghrelin and its co-secreted peptide obestatin in 44 patients with ischemic heart disease with that of 27 healthy matched controls. Here we first conducted using an immunohistochemistry assay to screen whether human salivary glands have any obestatin immunoreactivity. Then, serum and saliva obestatin and acylated ghrelin levels were determined by using Radioimmunoassay. Our immunohistochemical analysis demonstrated that obestatin was localized in the striated and excretory duct of human salivary gland. We also report for the first time that obestatin, like ghrelin, is present in human salivary gland and saliva. No evidence of the role of obestatin or ghrelin saliva levels in the context of ischemic heart disease was found. Salivary ghrelin and obestatin levels are correlated in controls with the blood levels. Determination of salivary values could represent a non-invasive alternative to serum ones that can be useful in clinical practice.     

Changes in Circulating Satiety Hormones in Obese Children: A Randomized Controlled Physical Activity‐Based Intervention Study

The aims of this study are to examine in children: (i) obesity‐related alterations in satiety factors such as leptin, ghrelin, and obestatin; (ii) the link between satiety factors and cardiometabolic risk factors; and (iii) the impact of a physical activity‐based lifestyle intervention on the levels of these satiety factors in the obese. We studied a total of 21 adolescents (BMI percentile, 99.0 ± 0.6 for 15 obese and 56.2 ± 1.1 for 6 lean). The obese subjects underwent a 3‐month randomized controlled physical activity‐based lifestyle intervention. Leptin, soluble leptin receptor (sOB‐R), ghrelin, and obestatin levels were determined as the primary outcome measures. Other markers of cardiometabolic disease such as inflammation and insulin resistance were also determined. Body composition was measured by dual‐energy X‐ray absorptiometry. The concentrations of ghrelin, obestatin, and sOB‐R were significantly lower in the obese children compared to the lean controls, whereas that of leptin was higher (all P < 0.05). Although intervention led to a net increase in obestatin (P < 0.01) and no change in ghrelin levels, the balance between ghrelin and obestatin (ratio of ghrelin to obestatin, G/O) decreased (P < 0.02). Intervention reduced leptin and increased sOB‐R (P < 0.01 for both). Significant associations between satiety factors and other cardiometabolic risk factors were also observed. Taken together, alterations in the levels of satiety factors are evident early in the clinical course of obesity, but physical activity‐based lifestyle intervention either prevented their continued increase or normalized their levels. These beneficial effects appear to aid in the maintenance of body weight and reduction in cardiovascular risk.     

血清胃蛋白酶原联合G-17对萎缩性胃炎及胃癌早期诊断价值

目的:探索检测血清胃蛋白酶原Ⅰ(PGⅠ)、胃蛋白酶原Ⅱ(PGⅡ)、胃泌素-17(G-17)在萎缩性胃炎及胃癌中的诊断价值。方法:收集医院2015年2月至12月门诊及住院的慢性非萎缩性胃炎44例(非萎缩性胃炎组),慢性萎缩性胃炎47例(萎缩性胃炎组),早期胃癌42例(胃癌组)。采用酶联免疫吸附试验(ELISA)测定各组血清PGⅠ、PGⅡ、G-17的水平,同时计算PGⅠ/PGⅡ的比值(PGR),比较各组指标间的差异,同时绘制各指标筛查萎缩性胃炎及胃癌的受试者工作曲线(ROC)曲线,分别评价其诊断价值。结果:胃癌组及萎缩性胃炎组的血清PGⅠ、PGR水平较非萎缩性胃炎组明显下降,且胃癌组下降更明显,差异均具有统计学意义(P0.05),萎缩性胃炎组血清PGⅡ显著低于非萎缩性胃炎组,差异均具有统计学意义(P0.05);胃癌组的血清G-17水平较非萎缩性胃炎组及萎缩性胃炎组均升高,差异有统计学意义(P0.05)。血清PGⅠ筛查萎缩性胃炎的最佳界值为PGⅠ90 ng/m L,其灵敏度和特异度分别为71.5%和51.0%,血清PGR筛查萎缩性胃炎的最佳界值为PGR8,其灵敏度和特异度分别为71.9%和54.0%,血清G-17筛查萎缩性胃炎的最佳界值为G-175 pmol/L,其灵敏度和特异度分别为66.1%和64.0%。血清PGⅠ筛查胃癌的最佳界值为PGⅠ73 ng/m L,其灵敏度和特异度分别为86.0%和74.9%;血清PGR筛查胃癌的最佳界值为PGR3,其灵敏度和特异度分别为90.2%和62.5%;血清G-17筛查胃癌的最佳界值为G-174 pmol/L,其灵敏度和特异度分别为62.5%和61.3%。结论:胃癌及萎缩性胃炎患者血清PGⅠ、PGR水平下降明显,且胃癌患者的血清G-17异常升高,血清PG联合GS-17测定可用于萎缩性胃炎及胃癌的早期筛查。     

Gender Difference of Circulating Ghrelin and Leptin Concentrations in Chronic Helicobacter pylori Infection

Background:  Both ghrelin and leptin are important appetite hormones secreted from the stomach. We examined whether demographic background, Helicobacter pylori infection, or its related gastritis severity could be associated with circulating ghrelin and leptin levels.
Methods:  This study prospectively enrolled 341 dyspeptic patients (196 females, 145 males), who had received endoscopy to provide the gastric specimens over both antrum and corpus for histology reviewed by the updated Sydney's system. The fasting blood sample of each patient was obtained for total ghrelin and leptin analysis.
Results:  Without H. pylori infection, there were similar ghrelin levels between female and male patients. In the H. pylori -infected patients, the males had lower plasma ghrelin levels than females (1053 vs. 1419 pg/mL, p  < .001). Only in males, not in females, the H. pylori infection and its related acute and chronic inflammation scores were significantly associated with a lower ghrelin level ( p  ≤ .04). The multivariate regression disclosed that only the chronic inflammation score independently related to a lower ghrelin level. Only in males, the ghrelin levels ranked in a downward trend for the gastritis feature as with limited-gastritis, with antrum-predominant gastritis, and with corpus-gastritis (1236, 1101, and 977 pg/mL). Leptin level was not related to H. pylori -related gastritis, but positively related to body mass index.
Conclusion:  There should be a gender difference to circulating total ghrelin levels, but not leptin levels, in response to H. pylori infection and its related chronic gastritis.     

Is There a Possible Relation Between Atrophic Gastritis and Premature Atherosclerosis?

BACKGROUND: In this study, we have aimed to show the possible relation between atrophic gastritis and premature atherosclerosis via hyperhomocysteinemia. MATERIALS AND METHODS: Thirty-four patients with atrophic gastritis were enrolled to the study. The control group consisted of 35 patients with non-atrophic gastritis. Classical cardiovascular disease risk factors did not significantly differ between atrophic gastritis and control subjects. The presence and degree of atrophic gastritis were assessed histologically and Helicobacter pylori infection was determined by both histologic and serologic methods. Body mass index was measured by standard technique blood fasting glucose, serum creatinine, total cholesterol, triglyceride, low-density lipoprotein cholesterol, high-density lipoprotein cholesterol, vitamin B12, folic acid, and homocysteine levels were measured by biochemical methods. Carotid intima-media thickness was measured by B-mode ultrasonography to examine the premature atherosclerosis. RESULTS: Plasma vitamin B12 levels were significantly lower (p = .00) and homocysteine levels were significantly higher (p = .01) in the atrophic gastritis group. There was no statistically significant difference in plasma folic acid levels between the two groups (p = .728). Carotid intima-media thickness was higher in the atrophic gastritis group than in the control group (0.516 mm versus 0.465 mm), but this difference did not show any statistical significance (p = .062). CONCLUSION: Our results showed that atrophic gastritis may cause hyperhomocysteinemia, which is an independent risk factor for atherosclerosis and cardiovascular diseases. However, when compared with controls, carotid intima-media thickness of the atrophic gastritis patients was found to be higher but did not reach statistically significant levels.     

Ghrelin and adipokines as circulating markers of disease activity in patients with Takayasu arteritis

Introduction

The current markers of disease activity in Takayasu arteritis (TA) are insufficient for proper assessment. We investigated circulating levels of unacylated and acylated ghrelin, leptin and adiponectin and their relationships with disease activity in patients with TA.

Methods

This study included 31 patients with TA and 32 sex-, age- and body mass index-matched healthy controls. Disease activity was assessed in TA patients using various tools, including Kerr''s criteria, disease extent index-Takayasu, physician''s global assessment, radiological parameters, and laboratory markers. Plasma unacylated and acylated ghrelin, and serum leptin and adiponectin levels were measured using an enzyme-linked immunosorbent assay.

Results

Unacylated and acylated ghrelin levels were found to be significantly lower in TA patients than that in healthy controls. Patients with active disease had lower unacylated ghrelin levels than those with inactive disease and had lower acylated ghrelin levels than healthy controls. Ghrelin levels were negatively correlated with various parameters of disease activity. The leptin/ghrelin ratio was significantly higher in TA patients than controls. It was positively correlated with disease activity. There was a positive correlation between unacylated and acylated ghrelin and a negative correlation between leptin and ghrelin. There was no statistical difference in adiponectin levels between TA patients and controls. The radiological activity markers were positively correlated with other parameters of disease activity.

Conclusions

This study suggests that plasma unacylated and acylated ghrelin levels may be useful in monitoring disease activity and planning treatment strategies for patients with TA. The serum leptin level and leptin/ghrelin ratio may also be used to help assess the disease activity.     

Increased plasma ghrelin levels in chronic renal failure are not associated with hemodynamic parameters.

BACKGROUND/AIMS: Hardly anything is known about the effect of renal function on plasma ghrelin levels. Ghrelin is an orexigenic hormone with important hemodynamic effects. We examined differences in plasma ghrelin levels between chronic renal failure (CRF) patients and healthy subjects, and ghrelin's relationship with indices of left ventricular (LV) function. METHODS: Fasting total plasma ghrelin levels were measured in 122 CRF patients (57 on, 65 not on hemodialysis) and 57 control subjects. Indices of LV function were evaluated using echocardiography. RESULTS: Total plasma ghrelin levels were higher in patients with CRF compared to controls, but were not different between patients on and those not on hemodialysis. In a multivariate linear regression model, presence of kidney dysfunction explained 41 % of the variability of ghrelin values. The etiology of renal failure (diabetic nephropathy or not) had no influence on ghrelin levels in the renal patients. Ghrelin levels were not associated with indices of LV systolic function or blood pressure in these patients. CONCLUSION: Fasting plasma ghrelin concentrations are higher in CRF patients regardless of their need for hemodialysis compared to controls. The etiology of renal failure does not have any effect on plasma ghrelin levels. In addition, ghrelin levels are not associated with hemodynamic parameters in patients with CRF.     

Tolbutamide inhibits gastrin release in man

Tolbutamide significantly decreased fasting plasma gastrin after 5 min of intravenous infusion in patients with atrophic gastritis, duodenal ulcer, or insulin-dependent diabetes mellitus (IDDM) as well as in healthy volunteers. Increased plasma insulin and decreased blood glucose were observed in patients with atrophic gastritis, duodenal ulcer and healthy volunteers, but not in patients with IDDM. Suppression of plasma gastrin in healthy volunteers was also observed following oral administration of tolbutamide. Despite the observed decrease in plasma gastrin, neither basal nor tetragastrin-stimulated acid output was changed for 30 min following tolbutamide infusion in healthy volunteers. Thus, our data suggest that tolbutamide inhibits gastrin release in man via mechanisms independent of changes in plasma insulin, blood glucose or acid secretion.