尾加压素Ⅱ对心脏的作用研究

发布时间：2018-02-24 19:37

本文关键词： 尾加压素II GPR14 一氧化氮硫化氢心梗心肌细胞免疫组化免疫荧光双标胱硫醚-γ-裂解酶蛋白印迹杂交逆转录一聚合酶链反应　出处：《复旦大学》2005年博士论文　论文类型：学位论文

【摘要】：尾加压素Ⅱ是最早从鱼的尾垂体分离出来的一种多肽,最近哺乳动物包括人的尾加压素Ⅱ已经被克隆出来。研究表明,尾加压素Ⅱ在心血管系统有重要作用,它曾被认为是最强的缩血管物质之一。对于不同种属的动物,静脉注射尾加压素Ⅱ产生的心血管反应有很大的差异,甚至对于同一种属的动物,报道也并不一致。尾加压素Ⅱ能增加人右心房肌的收缩力,但对左心室心肌的直接作用还有待阐明。尾加压素Ⅱ受体GPR14分布比较广泛,包括心血管组织,中枢和内分泌组织等。人们通过RT-PCR和配体受体结合实验证实GPR14在心血管的表达,但对于GPR14蛋白在心脏的表达以及它在心脏中分布的具体的细胞类型还缺乏直接的证据。另外,尾加压素Ⅱ可能会介导心肌细胞的肥大,在一些慢性缺氧或充血性心衰情况,尾加压素Ⅱ和其受体出现上调,推测尾加压素Ⅱ可能参与心血管的重构过程。一氧化氮具有舒张血管,保护心肌的作用。它参与尾加压素Ⅱ对心血管作用的调节。硫化氢是最近受到关注的具有生物活性的气体小分子,能抑制心肌收缩,舒张血管。但它是否参与尾加压素Ⅱ对心血管的作用,还需要进一步的研究。我们主要通过免疫组化和免疫荧光双标的方法观察GPR14在心脏中的表达,结果表明,GPR14主要表达于正常大鼠左心室的心肌细胞上,在心脏的其他部分包括心房,右心室和主动脉瓣膜没有观察到GPR14蛋白的阳性表达;在心脏中其他的细胞包括冠脉血管的内皮和平滑肌细胞上未见GPR14的表达。我们利用Western blot和逆转录—聚合酶链的方法进一步证实GPR14蛋白和基因确实表达在左心室。我们又通过免疫组化的方法观察GPR14蛋白在大鼠心梗后3天和2周梗塞区边缘的表达,结果表明,与假手术组相比,GPR14在表达的量和表达的细胞类型上,均没有出现明显的变化。在房间隔缺损病人的右心房,我们观察到GPR14受体的表达,主要在靠近心外膜的心肌组织;而在右心耳,GPR14蛋白的表达与血管分布有关。为了从功能学上进一步证实尾加压素Ⅱ受体确实表达在左心室的心肌上,我们观察了尾加压素Ⅱ对左室乳头肌的作用,结果提示,尾加压素增加左室乳头肌的收缩强度,但并不改变其他的收缩参数,包括收缩舒张速率,收缩潜伏期,达到最大收缩张力的时间以及舒张到一半的时间。我们还观察了给麻醉大鼠静脉注射尾加压素Ⅱ引起的心血管效应,主要引起左室收缩压,股动脉收缩压和舒张压,心率的下降;心肌收缩力(dp/dt)和心肌舒张能力(-dp/dt)的减弱;左室舒张压的升高:提示尾加压素Ⅱ可能对心脏具有抑制作用。我们推测在整体实验中,尾加压素Ⅱ可能通过调节其他物质如一氧化氮和硫化氢等气体小分子
[Abstract]:Urotensin II is a polypeptide from as early as the tail of a fish pituitary separated, including the tail recently vasopressin II mammals have been cloned. The results showed that urotensin II plays an important role in the cardiovascular system, it was considered to be one of the strongest vasoconstrictor for different species. Animal, intravenous urotensin II the cardiovascular response is very different, even for the same species of animal, reports are not the same. Urotensin II can increase the contractility of right atrium, but the direct effect on left ventricular myocardium still remains to be elucidated. Angiotensin II receptor is widely urotensin the distribution of GPR14, including cardiovascular tissues, central and endocrine tissues. People with GPR14 in cardiovascular experiments confirmed that the expression of RT-PCR through ligand receptor and GPR14 protein in the heart, but for the expression and its distribution in the heart The specific cell types is lack of direct evidence. In addition, urotensin II may be mediated by hypertrophy of cardiomyocytes, in chronic hypoxia or congestive heart failure, urotensin II and its receptor up-regulated, urotensin II that may be involved in cardiovascular remodeling process. Nitric oxide with vasodilator effect, myocardial protection. It is involved in the regulation of urotensin II on cardiovascular effects. Hydrogen sulfide is the recent attention of bioactive molecules, can inhibit myocardial contractility, relaxation of blood vessels. But whether it is involved in the tail function of vasopressin on cardiovascular, further research is needed.
We mainly through immunohistochemistry and double immunofluorescence method to observe expression of GPR14 in the heart, results showed that GPR14 was mainly expressed in the normal left ventricle of rat myocardial cells, in other parts of the heart including atrial, right ventricular and aortic valve was not observed in the positive expression of GPR14 protein in the heart of the other; there was no expression of GPR14 cells including coronary vascular smooth muscle cells and endothelial cells. We use the method of Western blot and reverse transcriptase polymerase chain further confirmed that GPR14 protein and gene expression in the left ventricle. We did observe by immunohistochemistry GPR14 protein in rats after myocardial infarction, 3 days and 2 weeks of infarction zone edge the results show that, compared with the sham operation group, and the expression of GPR14 in the amount of cell types, there was no obvious change. Right atrium in atrial septal defect patients, I The expression of the GPR14 receptor was observed mainly in the cardiac tissue near the epicardium, while in the right auricle, the expression of GPR14 protein was associated with the distribution of blood vessels.
In order to further study on function of urotensin II receptor that has been expressed in the left ventricular myocardium, we observed the effect of urotensin II, on the left ventricular papillary muscle showed that urotensin increased left ventricular papillary muscle contraction strength, but does not change the other parameters including systolic, diastolic and systolic velocity contraction, latency, maximum contraction time and diastolic to half the time. We also observed the anesthetized rat was urotensin II induced cardiovascular effects, mainly caused by left ventricular systolic pressure, systolic arterial pressure and diastolic blood pressure, heart rate decreased; myocardial contractility and diastolic (dp/dt) capacity (-dp/dt) decreased; left ventricular diastolic pressure elevated urotensin II may have inhibitory effects on the heart. We speculate that in vivo, urotensin II may regulate other substances such as nitric oxide Small molecules of gas, such as hydrogen sulfide

【学位授予单位】：复旦大学
【学位级别】：博士
【学位授予年份】：2005
【分类号】：R33

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