LONG-TERM REGULATION OF THE MICROCIRCULATION

对肾性高血压大鼠的急性研究表明， 结构变化的发生，有助于增加周边 阻力 研究表明，早期血管收缩的增加 被结构变化所取代，例如 微血管，小动脉大小减少， 壁厚 需要长期研究来记录这些变化， 在高血压的发展过程中， Vasomotion是一种 是血管阻力和血流调节重要因素 在有意识的动物身上研究得最好。 这是我们的目的 研究和记录所有这些机制在意识 肾性高血压家兔耳腔制备。 测量 将由微血管直径和血管运动的图像分裂 闭路电视显微镜，双缝红细胞速度 闪光灯电视毛细血管血细胞比容光度测定法 显微镜和微血管密度通过体内定量体视学。 微血管反应将在以下开始进行研究： 单肾和双肾1夹模型中的高血压，直至达到新的稳态 状态达到，大约2-6个月。 血压测量 血浆肾素活性的血液样品将从慢性 腹主动脉里的导管 在这些基线测量之后 数据，实验将进行研究的机制，导致 变化，如交感神经的影响， 肾素-血管紧张素系统和肌源性反应，增加和减少 腔内压 在其他研究中，将不夹闭肾动脉 在高血压成为不可逆性之前和之后， 的结构变化，看看他们是否发挥任何作用， 长期肾性高血压的不可逆性。 这些研究在 清醒家兔将提供信息，以评估形态学和 高血压和低血压的功能变化，它们的时间尺度， 病因及长期调节血液的功能意义 流

Acute studies in renal hypertensive rats indicate that functional and structural changes occur that contribute to the increase in peripheral resistance. The studies suggest that an early increase in vasoconstriction is superseded by structural alterations such as rarefaction of microvessels, reduction in arteriolar size, and increases in arteriolar wall thickness. Chronic studies are needed to document these changes on a daily basis during the development of hypertension. Vasomotion is an important contributor to vascular resistance and blood flow regulation which is studied best in conscious animals. It is the purpose of this study to examine and document all of these mechanisms in the conscious renal hypertensive rabbit using the ear chambter preparation. Measurements will be made of microvessel diameters and vasomotion by image splitting closed circuit television microscopy, red cell velocity by the dualslit photometric technique, capillary hematocrit by strobe-flash television microscopy, and microvessel density by in vivo quantitative stereology. Microvascular responses will be studied following the initiation of hypertension in the 1-kidney and 2-kidney-1-clip models until a new steady state is reached, approximately 2-6 months. Blood pressure measurements and blood samples for plasma renin activity will be obtained from a chronic catheter in the abdominal aorta. After these measurements of baseline data, experiments will be performed to study the mechanisms leading to the changes, such as the influence of the sympathetic nerves, the renin-angiotensin system, and myogenic responses to increased and decreased intralumenal pressure. In other studies the renal artery will be unclipped before and after hypertension becomes irreversible to study the regression of the structural changes and to see if they play any role in the irreversibility of long term renal hypertension. These studies in the conscious rabbit will provide the information to assess morphological and functional changes in hypertension and hypotension, their time scale, cause, and functional significance concerning long term regulation of blood flow.