高脂饮食喂养的大鼠胸主动脉对5-羟色胺和血管紧张素II的收缩反应增强。
Increased contractile responses to 5-Hydroxytryptamine and Angiotensin II in high fat diet fed rat thoracic aorta.
作者信息
Ghatta Srinivas, Ramarao Poduri
机构信息
Department of Pharmaceutical Sciences, North Dakota State University, Fargo, North Dakota 58105, USA.
出版信息
Lipids Health Dis. 2004 Aug 2;3:19. doi: 10.1186/1476-511X-3-19.
BACKGROUND
Feeding normal rats with high dietary levels of saturated fat leads to pathological conditions, which are quite similar to syndrome X in humans. These conditions such as hypertriglyceridemia, hypercholesterolemia, obesity, and hyperglycemia might induce hypertension through various mechanisms. Metabolic syndrome and the resulting NIDDM represent a major clinical challenge because implementation of treatment strategies is difficult. Vascular abnormalities probably contribute to the etiology of many diabetic complications including nephropathy, neuropathy, retinopathy, and cardiomyopathy. It has been shown that in Streptozotocin induced diabetic animals there is an increase in maximal responses to 5-Hydroxytryptamine and Angiotensin II. The purpose of this study was to evaluate High fat diet fed rats for the development of hypertriglyceridemia, hypercholesterolemia, hyperinsulinemia and hyperglycemia and to assess their vascular responses to 5-Hydroxytryptamine and Angiotensin II.
METHODS
Male Sprague Dawley rats were used for this study and were divided into two equal groups. One of the groups was fed with normal pellet diet and they served as the control group, whereas the other group was on a high fat diet for 4 weeks. Body weight, plasma triglycerides, plasma cholesterol, and plasma glucose were measured every week. Intraperitoneal glucose tolerance test was performed after 4 weeks of feeding. At the end of fourth week of high fat diet feeding, thoracic aortae were removed, and cut into helical strips for vascular reactivity studies. Dose-response curves of 5-Hydroxytryptamine and Angiotensin II were obtained.
RESULTS
There was no significant difference in pD2, with 5-Hydroxytryptamine and Angiotensin II in both groups but Emax was increased.
CONCLUSIONS
These results suggest that hypertension in high fat diet rats is associated with increased in vitro vascular reactivity to 5-HT and Ang II.
背景
用高膳食水平的饱和脂肪喂养正常大鼠会导致病理状况，这与人类的X综合征非常相似。这些状况如高甘油三酯血症、高胆固醇血症、肥胖症和高血糖症可能通过各种机制诱发高血压。代谢综合征及由此导致的非胰岛素依赖型糖尿病是一项重大的临床挑战，因为实施治疗策略很困难。血管异常可能在包括肾病、神经病变、视网膜病变和心肌病在内的许多糖尿病并发症的病因中起作用。研究表明，在链脲佐菌素诱导的糖尿病动物中，对5-羟色胺和血管紧张素II的最大反应增加。本研究的目的是评估高脂饮食喂养的大鼠是否会出现高甘油三酯血症、高胆固醇血症、高胰岛素血症和高血糖症，并评估它们的血管对5-羟色胺和血管紧张素II的反应。
方法
本研究使用雄性斯普拉格-道利大鼠，并将其分为两组。其中一组喂食正常颗粒饲料，作为对照组，而另一组则高脂饮食4周。每周测量体重、血浆甘油三酯、血浆胆固醇和血浆葡萄糖。喂养4周后进行腹腔葡萄糖耐量试验。在高脂饮食喂养的第四周结束时，取出胸主动脉，切成螺旋条用于血管反应性研究。获得了5-羟色胺和血管紧张素II的剂量-反应曲线。
结果
两组中5-羟色胺和血管紧张素II的pD2无显著差异，但最大效应增加。
结论
这些结果表明，高脂饮食大鼠的高血压与体外血管对5-羟色胺和血管紧张素II的反应性增加有关。
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