腹型肥胖个体血浆obestatin水平研究

目的 探讨腹型肥胖患者obestatin的血浆水平及与腰围的相关性.方法 入选腹型肥胖组患者50例（男性腰围≥85cm,女性腰围≥80cm）,及正常对照组20例（男性腰围＜85cm,女性腰围＜80cm,24 kg/m2＞ BMI≥18.5 kg/m2）.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.结果 腹型肥胖个体均表现出高的HOMA-IR、血清胆固醇及甘油三酯水平及低的高密度脂蛋白水平.与正常对照组相比,腹型肥胖组个体的血浆obestatin水平有所下降.在腹型肥胖的个体中,血浆obestatin水平与腰围及体重指数呈负相关.结论 腹型肥胖组的血浆obestatin水平明显降低,而且obestatin水平与腰围呈负相关,提示obestatin与脂肪分布及腹型肥胖的发生有关.     

Influence of short- and long-term treadmill exercises on levels of ghrelin, obestatin and NPY in plasma and brain extraction of obese rats

This study aims to clarify the effects of exercise on levels of appetite regulatory hormones in plasma and hypothalamus of obese rats. Diet-induced obese rats undergo short- (40 min) and long-term (40 min, 5 days/week for 8 weeks) exercises. The rats ran at a speed of 20 m/min on a 5° slope treadmill. Rats undergoing short-term exercise were divided into C, E0, E1, E3, E12, and E24. Rats undergoing long-term exercise (LE) were compared to long-term control (LC). Concentrations of ghrelin, obestatin, and neuropeptide Y (NPY) were measured using radio immuno-assay. Expression of ghrelin receptor (GHSR-1a), putative obestatin receptor (GPR-39), and NPY in the hypothalamus was measured by quantitative RT-PCR. After short-term exercise, the plasma concentrations of ghrelin and obestatin were not changed, but NPY decreased. Ghrelin and obestatin in the hypothalamus decreased, and recovered 12 until 24 h. NPY increased and recovered after 24 h. Expression of GHSR-1a and NPY was not changed and GPR-39 was not observed. In LE, these changes are different in plasma and hypothalamus. It would be concluded appetite and body weight of obese rats are decreased by exercise through reduced level of ghrelin in the hypothalamus. Obestatin seems to have no effect in exercise-induced change in appetite.     

Regulatory neuropeptides (ghrelin,obestatin and nesfatin-1) levels in serum and reproductive tissues of female and male rats with fructose-induced metabolic syndrome

Although, the exact mechanisms underlying the development of the metabolic syndrome (MetS) are not still completely understood, obesity, circulated peptide hormone levels and their interaction with genetic factors are considered largely responsible. The purpose of this study is to explore how the levels of ghrelin, obestatin (OBS) and NUCB2/nesfatin-1 (NES)/NUCB2 change in serum and the reproductive tissues of female and male rats with fructose-induced metabolic syndrome, and whether the levels of each hormone is correlated with the hormones involved with fertility. Experiments were conducted on 5-week-old Sprague–Dawley male and female rats assigned to either a control group or a MetS group. Controls were fed standard rat food and water ad libitum, while the MetS group was fed standard food with 10% (v/v) fructose solution added to their drinking water for 12 weeks with a 12/12 h photoperiod circle. Then, all animals were sacrificed after a one night fast. Peptides levels in the serum and reproductive tissues of rats were studied using the ELISA method while the immunoreactivity of reproductive system peptide hormones were shown by immunohistochemical staining method. Furthermore, the other biochemical parameters were measured using Konelab-60 equipment and infertility hormones were measured with Immulite2000. Fasting serum insulin, glucose, triglyceride, alanine aminotransferase (ALT), gamma glutamyl transpeptidase (GGT), low-density lipoprotein cholesterol (LDL-C), and total cholesterol (TC) levels were statistically significantly higher, and the amount of high density lipoprotein cholesterol (HDL-C) was significantly lower, in the MetS groups. Serum and tissue supernatant NES levels were significantly higher in the rats with MetS than the control group. Ghrelin, OBS and NES were expressed in the cytoplasm, concentrated around the apical parts of the epithelial cells in the reproductive tissues of the rats. The amounts of ghrelin were lower in the reproductive tissues of the animals with MetS, while NES levels in the same tissues increased. Obestatin also decreased, though not in the seminal glands.     

Different effects of ghrelin, des-acyl ghrelin and obestatin on gastroduodenal motility in conscious rats

Three peptides, ghrelin, des-acyl ghrelin and obestatin are derived from a common prohormone, preproghrelin by posttranslational processing, originating from endocrine cells in the stomach. To examine the effects of these peptides, we applied the manometric mea- surement of gastrointestinal motility in freely moving conscious rat models. Ghrelin exerts stimulatory ef- fects on the motility of antrum and duodenum in both fed and fasted state of animals. Des-acyl ghrelin exerts inhibitory effects on the motility of antrum, but not on the motility of duodenum in the fasted state of ani- mals. Obestatin exerts inhibitory effects on the motility of antrum and duodenum in the fed state, but not in the fasted state of animals. NPY Y2 or Y4 receptors in the brain may mediate the action of ghrelin, CRF type 2 receptors in the brain mediate the action of des-acyl ghrelin, whereas CRF type 1 and type 2 receptors in the brain mediate the action of obestatin. Vagal afferent pathways might be involved in the action of ghre- lin, but not involved in the action of des-acyl ghrelin, whereas vagal afferent pathways might be partially involved in the action of obestatin.     

Ghrelin/obestatin ratio in two populations with low bodyweight: constitutional thinness and anorexia nervosa

Constitutional thinness (CT) and anorexia nervosa (AN) are two categories of severely underweight subjects. Some appetite-regulating hormones display opposite levels in AN and CT. While levels of ghrelin, an orexigenic hormone, fit with the normal food intake in CT, the lack of efficacy of increased ghrelin levels in AN is not clear. Obestatin is a recently described peptide derived from the preproghrelin gene, reported to inhibit appetite in contrast to ghrelin. The aim of this study was to determine whether the circadian profile of obestatin, total and acylated ghrelin levels is different in CT subjects when compared with AN patients. Six-points circadian profiles of plasma obestatin, acylated ghrelin, total ghrelin and other hormonal and nutritional parameters were evaluated in four groups of young women: 10 CT, 15 restricting-type AN, 7 restored from AN and 9 control subjects. Obestatin circadian levels were significantly higher in AN (p<0.0001) while no difference was found between CT and control subjects. Acylated and total ghrelin were found increased in AN. Acylated ghrelin/obestatin and total ghrelin/obestatin were found decreased in AN compared to CT or C subjects (p<0.05). The percentage of acylated ghrelin was found decreased in CT group (p<0.05). The decreased ghrelin/obestatin ratio found in AN might participate in the restraint in nutriment intake of these patients. In contrast, in CT a lower percentage of acylated over total ghrelin might be considered in the aetiology of this condition.     

胃促生长素的胃肠动力学作用研究进展

胃促生长素(ghrelin)对胃肠动力作用机制是目前研究热点。ghrelin在外周作为饥饿信号分子可提高食欲、增加摄食,诱发移行性复合运动III相提前出现,加速胃排空。最近研究表明,ghrelin基因还可编码合成另一胃肠动力作用相反的肽—obestatin;下丘脑、迷走神经、肠神经系统参与了ghrelin对胃肠动力的生理调节作用。     

冠状动脉粥样硬化心脏病患者外周血Obestatin的检测及临床意义

目的观察冠状动脉粥样硬化心脏病(CHD)患者空腹外周血Obestatin水平的变化,并探讨其临床意义。方法选取92例行冠状动脉造影住院患者,根据造影结果分为对照组21例和冠状动脉粥样硬化组71例,计算冠状动脉粥样硬化组患者的Gensini积分,检测两组患者的血清Obestatin水平,并分析Obestatin水平与Gensini积分之间的相关性。结果冠状动脉粥样硬化组Obestatin水平较对照组显著升高(P<0.01)。根据Gensini积分将冠状动脉粥样硬化组患者分为1~30分组、31~90分组及>90分组,各组间血清Obestatin浓度差异无统计学意义(P>0.05)。结论 CHD患者的外周血Obestatin水平显著升高,推测Obestatin可能是CHD的一个危险因子,但Obestatin水平与CHD患者病变程度无显著性关系。     

妊娠期糖尿病患者肥胖抑制素水平与胰岛素抵抗的关联性研究

目的:研究妊娠期糖尿病患者肥胖抑制素水平与胰岛素抵抗的关联性。方法:选取我院2009年10月-2012年9月收治的孕周为22～30周的经确诊为妊娠期糖尿病的患者50例,同期正常孕妇45例,抽血监测相关指标。结果:对照组TCH、HLC水平与研究组比较,差异无统计学意义,两组数据相当;对照组TC、FG、GHL和空腹血糖水平明显低于研究组,P<0.05;对照组OIL水平高于研究组,P<0.05;两组比较,HOMA具有统计学差异,P<0.05。另外,采用多元回归分析,选取因变量为OIL,自变量为HOMA,得回归系数为-8.497 6,P=0.005。结论:胰岛素抵抗是影响妊娠期糖尿病患者肥胖抑制素水平的重要因素。