Divergent Roles of Nitric Oxide and Rho Kinase in Vasomotor Regulation of Human Retinal Arterioles
Divergent Roles of Nitric Oxide and Rho Kinase in Vasomotor Regulation of Human Retinal Arterioles
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DOI：
10.1167/iovs.09-4391
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发表时间：
2010-03-01
影响因子：
4.4
通讯作者：
Kuo, Lih
中科院分区：
文献类型：
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作者：
Hein, Travis W.;Rosa, Robert H., Jr.;Kuo, Lih
目的.虽然小动脉段有助于流量调节，但在单个微血管水平上关于血管功能如何在人视网膜中调节的信息很少。作者以前曾报道过血管反应性和其潜在的机制，在孤立的猪视网膜小动脉。在此，他们研究了人类视网膜小动脉进行比较。视网膜组织从7例接受眼球摘除术的患者中获得。分离人和猪的视网膜小动脉，并加压至55 cm H2 O管腔压力，以使用视频显微镜技术研究血管反应性。离体人和猪视网膜小动脉肌张力和扩张的剂量依赖于缓激肽，腺苷，硝普钠。管腔流量的逐步增加产生分级扩张，在测试的最高流量下扩张约60%。一氧化氮（NO）合酶抑制剂L-NAME几乎取消了缓激肽和流量的扩张，并减弱了腺苷诱导的扩张，而不改变对硝普钠的反应。内皮素-1引起剂量依赖性收缩。Rho激酶（ROCK）抑制剂H-1152阻断肌张力和内皮素-1诱导的收缩。视网膜小动脉对所有激动剂的反应和增加的流量在猪和人之间是相似的。分离的人视网膜小动脉扩张缓激肽和NO依赖性的方式增加流量。NO部分地促进腺苷诱导的血管舒张。相反，ROCK激活介导肌源性张力和内皮素-1诱导的血管收缩。人和猪视网膜小动脉之间的这些血管活性反应和潜在机制的相似性支持后者作为人类视网膜微循环的可行实验模型。（Invest Ophthalmol维斯科学。2010; 51：1583-1590）DOI：10.1167/iovs.09-4391
PURPOSE. Although the arteriolar segment contributes to flow regulation, there is sparse information at the single microvessel level on how vasomotor function is regulated in the human retina. The authors have previously reported vasoreactivity and its underlying mechanisms in isolated porcine retinal arterioles. Herein, they studied human retinal arterioles for comparison.METHODS. Retinal tissues were obtained from seven patients undergoing enucleation. Human and porcine retinal arterioles were isolated and pressurized to 55 cm H(2)O luminal pressure for vasoreactivity study using videomicroscopic techniques.RESULTS. Isolated human and porcine retinal arterioles developed myogenic tone and dilated dose dependently to bradykinin, adenosine, and sodium nitroprusside. Stepwise increases in luminal flow produced graded dilation with approximately 60% dilation at the highest flow tested. Nitric oxide (NO) synthase inhibitor L-NAME nearly abolished dilations to bradykinin and flow and attenuated the adenosine-induced dilation without altering the response to nitroprusside. Endothelin-1 caused dose-dependent constriction. Rho kinase (ROCK) inhibitor H-1152 blocked both myogenic tone and endothelin-1-induced constriction. Responses of retinal arterioles to all agonists and increased flow were similar between pigs and humans.CONCLUSIONS. Isolated human retinal arterioles dilate to bradykinin and increased flow in an NO-dependent manner. NO contributes, in part, to adenosine-induced vasodilation. Conversely, ROCK activation mediates myogenic tone and endothelin-1-induced vasoconstriction. Similarities in these vasoactive responses and the underlying mechanisms between human and porcine retinal arterioles support the latter as a viable experimental model of the human retinal microcirculation. (Invest Ophthalmol Vis Sci. 2010; 51: 1583-1590) DOI: 10.1167/iovs.09-4391