牦牛心脏组织结构的增龄性变化及相关因子的表达

发布时间：2018-05-14 21:17

本文选题：牦牛 + 心脏　；参考：《甘肃农业大学》2016年博士论文

【摘要】：牦牛是一种长期生活在海拔3000m以上高寒低氧地区的特殊物种,具有“高原之舟”的美称。在长期的生活状态下,牦牛在其生理、生化和基因方面都取得了稳定的遗传特性。已有研究证明,动物生活在低氧环境中容易引发高山病,最明显的是肺动脉高压和右心室肥厚,其中以牛科动物最为明显。目前,课题组已经对牦牛肺脏血管进行了大量研究,证明确实有自己的特点。目前牦牛心脏血管方面的研究主要集中在毛细血管床,牦牛心脏动脉和静脉及冠状动脉的解剖结构的研究方面。虽对冠状动脉进行了大量的研究,但年龄段划分不够细致,研究只停留在解剖结构的研究,也未见相关因子在血管和心肌组织上表达情况的报道。因此,本研究选取32粒牦牛心脏(1日龄、6月龄、1岁、2岁和5岁牦牛)作为研究对象,应用免疫组织化学技术、免疫电镜技术和Elisa检测技术对牦牛心肌组织结构和HIF-1a、VEGF、HSP27和HSP70蛋白在牦牛冠状动脉上的表达进行了定位和定量的研究,以期为心脏对低氧环境的适应机理提供理论依据,为高原医学的发展提供基础数据。结果显示:1.在牦牛不同的年龄阶段,心肌细胞超微结构呈现了规律性的变化,主要体现在线粒体、细胞膜和胶原纤维等方面。2.6月龄牦牛心脏内胶原纤维直径最大。随着年龄的增加,牦牛心脏内Ⅰ型胶原纤维数量逐渐增多。5岁时,牦牛心脏内以Ⅰ型胶原纤维占优势。3.在不同的年龄阶段,线粒体形态发生变化。1日龄牦牛心脏中线粒体聚集在核的周围,形态较圆。从5月龄至2岁,线粒体形态呈椭圆形,分散在肌原纤维之间,线粒体的嵴排列整齐。在5岁牦牛中心脏中出现矩形线粒体,嵴变得不规则。线粒体密度和活性的变化:线粒体复合物酶ⅠⅡ和Ⅴ的活性随年龄增大,而复合物酶Ⅲ和Ⅳ的活性从1日龄增大至1岁,之后逐渐下降。4.HIF-1a主要在冠脉的内皮细胞和心肌细胞有表达,在冠脉平滑肌细胞中未见表达。VEGF在内皮细胞和冠脉的平滑肌细胞中有表达,在心肌细胞中未见表达。空白对照中未见这两种蛋白表达。免疫电镜结果显示:HIF-1a蛋白在内皮细胞的胞核(弱信号)和胞质(强信号)表达,在心肌细胞胞质中有强信号表达,在平滑肌细胞上未见表达。VEGF蛋白在冠状动脉内皮细胞胞质(强信号)和胞核(弱信号)表达,在冠脉平滑肌细胞的胞核及核周表达。5.HIF-1a的分泌量在心肌组织和冠脉中,从1日龄开始一直增加至2岁,之后又下降。在1日龄和2岁之间的分泌量差异显著。然而,VEGF蛋白在心肌和冠脉中的分泌量随年龄增大持续增多。HIF-1a和VEGF的分泌量均左心室高于右心室,前降支高于左旋支。6.HSP27和HSP70蛋白在冠状动脉血管内皮细胞、心肌细胞的胞质中表达较强。HSP70蛋白还在中膜的平滑肌细胞核中强表达。HSP27基因在各个年龄段均左心室的表达量最高,其次是右心室、左心房和右心房。HSP70基因从6月龄开始左心室表达量较高。HSP27和HSP70基因的表达量均是心室高于心房。
[Abstract]:Yak is a special species living in alpine and hypoxic areas above 3000m altitude for a long time. It has the beauty of the "boat of Plateau". In the long life, yaks have obtained stable genetic characteristics in its physiological, biochemical and genetic aspects. At present, the research group has done a lot of research on the lung blood vessels of yak, which proved to have its own characteristics. At present, the research on the heart vessels of yaks is mainly focused on the capillary bed, the heart artery of yak, and the anatomical structure of the vein and coronary artery. Although a large number of studies have been carried out on the coronary artery, the age division is not meticulous, the study only stays in the study of anatomical structure, and there is no related factors in the expression of blood vessels and myocardium. Therefore, this study selected 32 yak hearts (1 days of age, 6 month old, 1 years, 2 and 5 Yyears) as the research object, The structure of yak myocardial tissue and the expression of HIF-1a, VEGF, HSP27 and HSP70 protein on the coronary artery of yak were studied by immuno histochemistry, immuno electron microscopy and Elisa detection, in order to provide a theoretical basis for the adaptation mechanism of the heart to hypoxia environment and provide the basis for the development of plateau medicine. The results showed that: 1. the ultrastructure of cardiac myocytes in the different age of yak showed a regular change, mainly in the mitochondria, cell membrane and collagen fiber, the diameter of collagen fiber in the heart of yak was the largest in.2.6 month old yak. With the increase of age, the number of type I collagen fibers in the yak heart gradually increased.5 years old, yak In the heart of the cattle, the type I collagen fiber occupies the dominant.3. in the different age stages. The mitochondrial morphogenesis changes in the heart of.1 yak. The mitochondria are round and round in the heart of the yak heart. From 5 month old to 2 years old, the mitochondria are elliptical in shape, scattered in the myofibrils, the ridge of the grain body is arranged neatly. It appears in the center of the yak at the age of 5. The mitochondrial density and activity change: the activity of mitochondrial complex enzyme I II and V increases with age, and the activity of complex enzyme III and IV increases from 1 days to 1 years old, and then.4.HIF-1a decreases mainly in the endothelial cells and cardiac myocytes in the coronary artery and is not found in the coronary smooth muscle cells. The expression of.VEGF was expressed in the smooth muscle cells of endothelial cells and coronary arteries, and no expression was found in the cardiomyocytes. No expression of these two proteins was found in the blank control. The results of immuno electron microscopy showed that the expression of HIF-1a protein in the nucleus (weak signal) and cytoplasm (strong signal) of the endothelial cells was strongly expressed in the cytoplasm of the cardiac myocytes, and the smooth muscle was fine in the smooth muscle cells. The expression of.VEGF protein in the cytoplasm (strong signal) and nucleus (weak signal) of the coronary artery endothelial cells was not expressed on the cell. The secretion of.5.HIF-1a expressed in the nucleus and peri of the coronary artery smooth muscle cells in the myocardial tissue and coronary artery, from 1 days of age to 2 years, and then decreased. The difference of secretion between 1 days and 2 years old was significant. However, the secretion of VEGF protein in the myocardium and coronary artery increased with age and the secretion of.HIF-1a and VEGF was higher than that of the right ventricle. The anterior descending branch was higher than the left branch.6.HSP27 and the HSP70 protein in the coronary vascular endothelial cells. The strong.HSP70 protein expressed in the cytoplasm of the cardiac myocytes was strong in the nucleus of the smooth muscle of the middle membrane. The expression of.HSP27 gene in the left ventricle was the highest at all ages, followed by the right ventricle, the left atrium and the right atrium, the.HSP70 gene was higher in the left ventricle from 6 month old and the expression of the HSP70 gene in the left ventricle was higher than that of the atrium.

【学位授予单位】：甘肃农业大学
【学位级别】：博士
【学位授予年份】：2016
【分类号】：S823.85

【相似文献】