PROSTAGLANDINS--THE KIDNEY AND HYPERTENSION

前列腺素——肾脏和高血压

• 批准号: 3565426
• 负责人: MICHAEL J DUNN
• 金额: $ 31.26万
• 依托单位: CASE WESTERN RESERVE UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 1977
• 资助国家: 美国
• 起止时间: 1977-09-01 至 1994-08-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/3565426
• 关键词: adenylate cyclase; adrenergic agents; angiotensin II; antihypertensive agents; calcium; gas chromatography; glomerular filtration; high performance liquid chromatography; kidney circulation; kidney metabolism; kidney transplantation; leukotrienes; mass spectrometry; nephrotic syndrome; platelet activating factor; prostaglandins; radioimmunoassay; renal glomerulus; renal hypertension; renal medulla; salt intake; spontaneous hypertensive rat; thin layer chromatography; thromboxanes; tissue /cell culture; vascular resistance; vasopressins

We propose experiments to study glomerular mesangial cells, in culture, in order to evaluate membrane receptors and signal transduction pathways activated by the vasoconstrictors, endothelin (ET) and thromboxane A2 (TxA2). We will quantitate receptor number, affinity and specificity and correlate receptor characteristics with cellular responses to these ligands. We will also evaluate the role of GTP binding proteins to link receptors to plasma membrane enzymes such as adenylate cyclase and phospholipases A, C and D. The role of G proteins will be measured in both intact cells and with cell membranes using stable GTP analogues. The capacity of phospholipase D to mediate cellular responses to ET and TxA2 will be studied as will the possibility that phospholipase C will use phospholipid substrates in addition to polyphosphoinositides. In subsequent studies, we will evaluate the importance of these signal transduction pathways to mediate the cellular responses of contraction and proliferation. Specifically, we will attempt to mimic proliferative and contractile actions of ET and TxA2 through changes of cellular inositol phosphates, (Ca2+)i pHi and protein kinase C activity. We will also attempt to dissociate phospholipase C activation from the membrane receptor through EJ-ras transfection of the mesangial cells. These manipulations will allow dissection of the relative importance of these signal transduction events either singly or in combination to mediate mesangial contraction and proliferation. Finally, we will search for a genetic defect of mesangial and vascular smooth muscle cells in genetically hypertensive strains. We propose that hyperresponsiveness of the phospholipase C signalling pathways may mediate enhanced vasoconstriction and reduced glomerular filtration. This theory will be tested using cultured vascular smooth muscle and mesangial cells with an assessment not only of their contractile and proliferative responses to contractile agonists but also a comparison of phospholipase C activation with measurements of (Ca2+)i, pHi, release of inositol phosphates and stimulation of protein kinase C.

我们提出了研究肾小球系膜细胞的实验， 培养，以评估膜受体和信号 由血管收缩剂、内皮素激活的转导途径 (ET) 和血栓素 A2 (TxA2)。 我们将定量受体 数量、亲和力和特异性以及相关受体 细胞对这些配体反应的特征。 我们将 还评估 GTP 结合蛋白连接受体的作用 质膜酶，例如腺苷酸环化酶和 磷脂酶 A、C 和 D。将测量 G 蛋白的作用 使用稳定的 GTP 在完整细胞和细胞膜中进行检测 类似物。 磷脂酶 D 介导细胞 将研究对 ET 和 TxA2 的反应以及可能性 磷脂酶 C 还将使用磷脂底物 为多磷酸肌醇。 在后续的研究中，我们将评估 这些信号转导途径对于介导的重要性 收缩和增殖的细胞反应。 具体来说， 我们将尝试模仿增殖和收缩行为 ET 和 TxA2 通过细胞磷酸肌醇的变化， (Ca2+)i pHi 和蛋白激酶 C 活性。 我们也会尝试 将磷脂酶 C 的激活与膜受体分离 通过EJ-ras转染系膜细胞。 这些 操纵将允许剖析相对重要性 这些信号转导事件可以单独或组合 介导系膜收缩和增殖。 最后，我们 将寻找系膜和血管平滑肌的遗传缺陷 遗传性高血压菌株中的肌肉细胞。 我们建议 磷脂酶 C 信号通路的高反应性可能 介导增强的血管收缩和减少的肾小球 过滤。 该理论将使用培养的血管进行测试 平滑肌和系膜细胞的评估不仅 他们对收缩的收缩和增殖反应 激动剂，还比较了磷脂酶 C 的激活情况 (Ca2+)i、pHi、磷酸肌醇释放的测量 刺激蛋白激酶C.