CALCIUM/IONS AND CAMP ROLE IN CAUSATION OF HYPERTENSION

这项提案的目的是调查生物化学变化 在自发性高血压大鼠（SHR）血管平滑肌中。 这些 研究的目的是进一步了解 增加了高血压模型中血管张力的发展。 实验旨在研究钙调素-和 cAMP依赖性蛋白激酶介导的肌浆蛋白磷酸化 从牛颈动脉分离的网状（SR）和肌膜（SL）囊泡 对Ca ~（++）摄取和（Ca ~（++），Mg ~（++））-ATPase活性的影响。 此外，我们将 研究钙调蛋白和cAMP依赖性蛋白激酶 在不同的位点磷酸化相同的蛋白质， 牛颈动脉SR和SL膜的不同蛋白质 动脉 我们将研究钙调素和cAMP依赖性的影响， 蛋白激酶介导的SR和SL囊泡的磷酸化， SHR和WKY对血管平滑肌Ca++摄取和（Ca++， Mg++）-ATP酶活性。 这些研究的目的是了解 减少Ca++螯合的分子机制 从SHR血管平滑肌中分离微粒体。 此夕h 假设SHR尾动脉条张力增加是由于 将测试收缩蛋白对Ca++的增加的反应性。 为了实现这一目标，我们将在带皮的尾动脉条中研究， SHR和WKY（i）对分级剂量Ca++的收缩反应，（ii） cAMP依赖性蛋白激酶催化亚基对心肌收缩作用 对Ca++的反应。 实验还旨在测试是否 SHR尾动脉条对去甲肾上腺素的反应性增加， Ca++是由于肌球蛋白轻链磷酸化增加。 将对分级剂量引起的张力发展进行估计 去甲肾上腺素使用完整的尾动脉条和分级剂量的 Ca++使用带皮尾动脉条。 肌球蛋白轻链长度 磷酸化将在稳态张力后定量 对于每个剂量的NE或Ca++的发育。 肌球蛋白轻链长度 磷酸化将与张力产生的程度相关， WKY和SHR尾动脉条。

The objectives of this proposal are to investigate the biochemical changes in vascular smooth muscle of spontaneously hypertensive rat (SHR). These studies are aimed to further our understanding of the mechanisms underlying increased vascular tension development in this model of hypertension. Experiments are designed to investigate the effect of calmodulin- and cAMP-dependent protein kinase mediated phosphorylation of sarcoplasmic reticulum (SR) and sarcolemma (SL) vesicles isolated from bovine carotid artery on Ca++ uptake and (Ca++, Mg++)-ATPase activity. Further, we will investigate whether calmodulin- and cAMP-dependent protein kinase phosphorylate the same protein at different sites or they phosphorylate different proteins of SR and SL membranes isolated from bovine carotid artery. We will investigate the effect of calmodulin- and cAMP-dependent protein kinase mediated phosphorylation of SR and SL vesicles isolated from vascular smooth muscle of SHR and WKY on Ca++ uptake and (Ca++, Mg++)-ATPase activity. The objective of these studies being to understand the molecular mechanisms underlying reduced Ca++ sequestration by microsomes isolated from vascular smooth muscle of SHR. Further, the hypothesis that increased tension in caudal artery strip of SHR is due to increased responsiveness of contractile proteins to Ca++ will be tested. To achieve this objective we will study in skinned caudal artery strips of SHR and WKY (i) contractile response to graded doses of Ca++, (ii) the effect of catalytic subunit of cAMP-dependent protein kinase on contractile responsiveness to Ca++. Experiments are also designed to test whether increased reactivity of caudal artery strips of SHR to norepinephrine and Ca++ is due to the increased myosin light chain phosphorylation. Estimations will be made of tension development in response to graded doses of norepinephrine using intact caudal artery strips and to graded doses of Ca++ using skinned caudal artery strips. The extent of myosin light chain phosphorylation will be quantitated after the steady-state tension development for each dose of NE or Ca++. The extent of myosin light chain phosphorylation will be correlated with the extent of tension generation in the caudal artery strips of WKY and SHR.