大黄素对2型糖尿病大鼠胃动力的影响及机制研究

目的:研究大黄素对2型糖尿病大鼠胃动力的影响及其机制。方法:以小剂量链脲佐菌素(STZ,30mg·kg-1)加长期高脂高糖饲料喂养复制大鼠2型糖尿病模型。复制成功后分别用大黄素、替加色罗、多潘立酮进行药物干预治疗6周,并设立正常对照组与模型组进行同期比较。实验结束时用单光子发射计算机断层扫描技术(SPECT)测定胃半排空时间(GET1/2)与90min胃内核素残留率(RIH);常规检测空腹血糖、血清胰岛素、三酰甘油(TG)、总胆固醇(TC)、高密度脂蛋白-胆固醇(HDL-C);并用放免法检测血浆和胃肠组织P物质(SP)、生长抑素(SS)的含量。结果:模型组大鼠的胃排空较正常对照组显著减慢(P<0·01),而大黄素、替加色罗及多潘立酮组大鼠的胃排空较模型组显著加快(P<0·01或P<0·05)。大黄素、替加色罗及多潘立酮组大鼠的血浆和胃肠组织SP较模型组显著升高,而SS显著降低(P<0·01或P<0·05)。模型、替加色罗及多潘立酮组大鼠血清TG和TC较正常对照组显著升高,而HDL-C显著降低(P<0·01),但大黄素组大鼠TG、TC和HDL-C可以得到纠正(P<0·01)。结论:大黄素可能通过纠正部分胃肠激素的异常表达提高2型糖尿病大鼠的胃动力。

Mechanism of Effects of Emodin on Gastric Dynamics in Type 2 Diabetic Rats

OBJECTIVE： To investigate the mechanism of the effects of Emodin on the gastric motility of type 2 diabetic rats. METHODS： Murine type 2 diabetes model was induced in rats by intravenous injection of a small dose of streptozotocin plus long- term high fat high caloric laboratory chow. Then the model rats were treated with Emodin（EMO）, tegaserod （TEG） or domperidone（DOM） for 6 weeks, with control（NOR） and model（MOD） groups as comparison. Gastric emptying half time（GET1/2） and 90 min residual rate（RIH） were measured by single photon emission computed tomography（SPECT） before sacrifice. The fasting blood glucose and serum insulin, riglycerides TG）, total cholesterol（TC）,high density lipoprotein cholesterol（HDL- C） were determined by biochemical methods. Plasma and tissue levels of substance P（SP） and somatostatin （SS） were determined using radioimmunoassay. RESULTS： Gastric emptying in model group was significantly slower than in normal control group（P 〈（0.01）, but were significantly sped up after treatment by Emodin, tegaserod or domperidone（P 〈0.01 or P 〈0.05） . Plasma and intestine levels of SP were significantly increased while SS were significantly decreased after treatment by emodin, tegaserod or domperidone as compared with model group（P 〈 0.01 or P 〈 0.05）. Serum TG and TC were significantly higher while HDL- C was lower in the model group and tegaserod or domperidone - treated group than those in normal group（P 〈0.01）, but serum TG, TC and HDL- C levels were regulated to normal in Emodin- treated group（P 〈 0.01）. CONCLUSION： Emodin can promote the gastrointestinal motility in type 2 diabetic rats is possibly related to its ability to regulate the abnormal expression of gastrointestinal hormones.