RENAL MEDULLARY NITRIC OXIDE AND BLOOD PRESSURE

我们实验室以前的数据证明了 肾髓质。一氧化氮合酶在肾脏近期和远期控制中的作用 功能和动脉压。个体一氧化氮合酶的作用 控制肾功能和动脉压的异构体是 不清楚。我们实验室最近的研究表明 诱导型一氧化氮合酶(INOS)在肾脏中含量较高 正常大鼠延髓与慢性全身性iNOS抑制导联 导致动脉血压升高。这项提案将解决 肾髓质诱导型一氧化氮合酶差异表达假说 正常大鼠肾髓质内不同细胞类型 通过在水平上的直接作用影响钠和水的排泄 科洛西导管的。 本提案的前半部分将进行实验，以 测定急、慢性水、电解质平衡及 选择性抑制肾髓质对血压的影响 伊诺斯。这些实验将使用技术进行 我们实验室独有的(用于激光的植入式光纤- 多普勒血流测量和选择性肾内直接输注 髓质间质)，因为肾髓质iNOS被抑制 用选择性的酶抑制剂。确认禁止遗嘱 用体外一氧化氮合酶活性测定方法测定 从处理过的动物身上获得的组织。这些实验将 证明诱导型一氧化氮合酶在钠调节中的重要性 水平衡和血压。 提案后半部分的实验将重点放在 诱导型一氧化氮合酶在肾小管中的分布及其功能意义 以及随着钠摄入量的改变而产生的血管节段。比较 信使核糖核酸水平，免疫反应蛋白水平，和钙- 依赖和非依赖的一氧化氮合酶活性最初将 对从饲养在 钠摄入量过低、正常或过高。定量RT-PCR 然后，将使用对iNOS的mRNA的测量来确定 INOS消息的位置和相对数量 显微解剖的肾髓质管和/或血管段。 最后，钠摄入量与血压的关系 长期给予选择性iNOS抑制剂的大鼠 将被确定为，以得出与 观察肾髓质结构诱导型一氧化氮合酶的变化。

Previous data from our laboratory demonstrated the importance of renal medullary. NOS in the short- and long-term control of renal function and arterial pressure. The role of the individual NOS isoforms in the control of renal function and arterial pressure is not clear. Recent work from our laboratory indicates that inducible NOS (INOS) is present in high levels in the renal medulla of normal rats and chronic systemic iNOS inhibition leads to an elevation of arterial pressure. This proposal will address the hypothesis that renal medullary iNOS is differentially expressed in different cell types in the renal medulla of normal rates and influences sodium and water excretion by direct effects at the level of the colocynth duct. Experiments will be performed in the first half of this proposal to determine the acute and chronic fluid and electrolyte balance and blood pressure effects of selective inhibition of renal medullary iNOS. These experiments will be performed using techniques unique to our laboratory (implanted optical fibers for laser- Doppler flometery and selective infusion directly into the renal medullary interstitial space) as renal medullar iNOS is inhibited with selective enzyme inhibitors. Confirmation of inhibition will be determined by in vitro measures of NOS enzyme activity in tissues obtained from the treated animals. These experiments will demonstrate the importance of iNOS in the regulation of sodium and water balance and blood pressure. The experiments in the second half of the proposal will focus on the distribution and functional importance of iNOS in renal tubular and vascular segments as sodium intake is changed. comparison of mRNA levels, immunoreactive protein levels, and calcium- dependent and -independent NOS enzymatic activity will initially be performed on whole tissue obtained from rats maintained on a low, normal, or high sodium intake. Quantitative RT-PCR measurements of mRNA for iNOS will then be used to determine the location and relative quantity of iNOS message in microdissected renal medullary tubular and/or vascular segments. Finally, the relationship between sodium intake and blood pressure in rats chronically administered with the selective iNOS inhibitors will be determined to in order to draw a functional correlate with the observed changes in iNOS in renal medullary structures.