流体剪切力对肺动脉内皮细胞一氧化氮合酶表达的影响

发布时间：2018-01-26 08:08

本文关键词： 肺动脉高压血流动力学内皮型一氧化氮合酶　出处：《山东大学》2012年硕士论文　论文类型：学位论文

【摘要】：研究背景：一氧化氮（nitric oxide,NO)是内皮细胞分泌的重要血管活性物质，具有扩张血管和抑制血管平滑肌细胞增殖的功能。左旋精氨酸在内皮型一氧化氮合酉每（endothelial nitric oxide synthase, eNOS)催化下合成NO，eNOS是该反应的限速酶，故eNOS表达水平高低直接决定内皮细胞NO分泌的多少。左向右分流型先天性心脏病（congenital heatr disease,CHD)的病理生理变化表现为肺循环血流显著增多。由于血管内皮细胞附着于血管腔内壁，故高肺血流可直接造成肺动脉内皮细胞（pulmonary atreiral endothelial cells, PAECs)所受剪切力(shear stress,SS)增加，从而引起PAECs形态和功能改变。关于NO在尚肺血流所致肺动脉尚压(pulmonary hypetrension,PH)的过程中的作用目前尚无一致性意见，且多数实验研究或为慢性损伤因素处理的动物实验，或为中晚期病人手术活检或死后尸检病例研究，即多数研究局限于肺动脉高压慢性或中晚期分子病理事件，而内皮细胞合成分泌的NO及其限速酶eNOS在早期是否受到影响却鲜有报道。研究目的：研究流体剪切力对大鼠PAECs eNOS表达的影响，探讨高肺血流肺动脉高压早期的病理生理变化。研究方法：应用体外流室装置系统，按静态组(0dyn/cm2)、低剪切力组(ldyn/cm2)、高剪切力组（3dyn/cm2)对PAECs施加不同剪切力。RT-PCR法测定不同剪切力对PAECs eNOS基因表达的影响；Westenr blot法检测不同剪切力对PAECs eNOS蛋白表达的影响。结果：RT-PCR结果示，高、低剪切力组eNOS mRNA表达明显高于对照组(p0.05),且剪切力越大eNOS mRNA表达越高；Western blot结果示，高、低剪切力组eNOS蛋白表达水平较对照组增高（p0.05)，但高剪切力组与低剪切力组之间eNOS蛋白表达水平差异不显著。结论：流体剪切力能够明显上调PAECs eNOS基因及蛋白表达，，提示eNOS表达上调可能在高血流致肺动脉高压形成的早期阶段发挥重要的代偿性作用。
[Abstract]:Background: nitric oxide (no) is an important vasoactive substance secreted by endothelial cells. It has the function of dilating blood vessels and inhibiting the proliferation of vascular smooth muscle cells. Endothelial nitric oxide synthase. The synthesis of NON-Enos catalyzed by Enos is the rate-limiting enzyme of this reaction. Therefore, the level of eNOS expression directly determines the amount of no secretion in endothelial cells. Left to right shunt congenital heart disease congenital heatr disease. The pathophysiological changes of CHD were as follows: pulmonary circulatory blood flow was significantly increased, and vascular endothelial cells were attached to the inner wall of vascular cavity. Therefore, high pulmonary blood flow can directly cause pulmonary atreiral endothelial cells in pulmonary endothelial cells. The shear stress of pacs) increased. Therefore, the morphological and functional changes of PAECs were observed. No was found in pulmonary hypetrension of pulmonary artery induced by pulmonary blood flow. There is no consensus on the role of PHs in the process, and most of the experimental studies have been done in animals that deal with chronic injury factors, or in surgical biopsies or postmortem studies of patients in the middle and late stages of the disease. That is, most of the studies are confined to chronic or late molecular pathological events of pulmonary hypertension. However, whether the no and its rate-limiting enzyme eNOS were affected in the early stage of endothelial cells was rarely reported. Objective: to study the effect of fluid shear stress on the expression of PAECs eNOS in rats. To investigate the pathophysiological changes in the early stage of pulmonary hypertension with high pulmonary blood flow. Methods: the external flow chamber system was used according to the static group (0 dyn / cm ~ (2)) and the low shear stress group (n / m ~ (2)). The effect of different shear stress on the expression of PAECs eNOS gene was determined by different shear stress and RT-PCR method in high shear stress group (3 dyn / cm ~ (2)). Westenr blot assay was used to detect the effect of different shear stress on the expression of PAECs eNOS protein. The expression of eNOS mRNA in the low shear stress group was significantly higher than that in the control group, and the higher the shear stress was, the higher the eNOS mRNA expression was. The results of Western blot showed that the expression of eNOS protein in the high and low shear stress groups was higher than that in the control group (p0.05). But there was no significant difference between the high shear stress group and the low shear stress group in the expression of eNOS protein. Conclusion: fluid shear stress can obviously up-regulate the expression of PAECs eNOS gene and protein. The results suggest that the up-regulation of eNOS expression may play an important compensatory role in the early stage of pulmonary hypertension induced by high blood flow.
【学位授予单位】：山东大学
【学位级别】：硕士
【学位授予年份】：2012
【分类号】：R725.4

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