EFFECT OF VASOACTIVE AGENTS IN THE ISOLATED GLOMERULUS

问题：在文献中有相当数量的数据 提示单个肾单位肾小球滤过率受 血管活性荷尔蒙。这些荷尔蒙包括前列腺素， 血管紧张素II、去甲肾上腺素和加压素。它们的作用机制 到目前为止，这些激素调节肾小球滤过 几乎只在活体条件下进行研究。在这些下面 在某些情况下，一种激素调节的单一效果是困难的 由于这些代理人的许多系统性影响和 可能发生的荷尔蒙-荷尔蒙相互作用。 目标：在本项目中，调查 血管活性物质：前列腺素E_2、前列环素、缓激肽、乙酰胆碱、血管紧张素II、 去甲肾上腺素和加压素对肾小球滤过决定因素的影响 提出了速率(PGC、PI GC、KF)。该项目的第二个目标将是 量化单个肾小球产生的TxB2、PGE和PGI2。 此外，这种产物对血管活性物质的反应： 将测量血管紧张素II、去甲肾上腺素和加压素。 方法：上述目标将通过使用 本实验室最新开发的技术：隔离灌流 肾小球。这项技术使人们能够测量单个 血管活性化合物在受控条件下消除全身性 减少荷尔蒙-荷尔蒙之间的相互作用。它还允许人们 测定单个肾小球前列腺素和血栓素B_2的产生 生理流率。简而言之，一个人游离地解剖一个肾小球。 有完整的传入和传出小动脉。这个肾小球 保留完整的胶囊被转移到灌流装置， 使用两套移液管：一套用于通过传入灌流 小动脉和肾小球静水压力的测量， 第二种，用于从传出小动脉收集液体。使用 这项技术可以测量PGC、PI GC、SNGFR、QA和滤过率 分数，一人可以计算KF。

Problem: There is a considerable amount of data in the literature which suggests that single nephron glomerular filtration rate is influenced by vasoactive hormones. These hormones include the prostaglandins, angiotensin II, norepinephrine, and vasopressin. The mechanisms by which these hormones modulate glomerular filtration have until now been investigated almost exclusively under in vivo conditions. Under these conditions, the singular effect of one hormonal manipulation is difficult to decipher due to the many systemic effects of these agents and the possible hormone-hormone interactions that may occur. Objectives: In the present project an investigation of the effects of the vasoactive agents: PGE2, PGI2, bradykinin, acetylcholine, angiotensin II, norepinephrine and vasopressin on the determinants of glomerular filtration rate (PGC, Pi GC, Kf) is proposed. A second aim of this project will be to quantify the production of TxB2, PGE, and PGI2 by a single glomerulus. Further, the response of this production to the vasoactive agents: angiotensin II, norepinephrine, and vasopressin will be measured. METHODS: The above objectives will be approached with the use of a technique recently developed in this laboratory: the isolated perfused glomerulus. This technique allows one to measure the effect of a single vasoactive compound under controlled conditions which eliminate systemic effects and minimize hormone-hormone interactions. It also allows one to measure the prostaglandin and TxB2 production by a single glomerulus under physiologic flow rates. Briefly, one dissects a single glomerulus free with intact afferent and efferent arterioles. This glomerulus which retains an intact capsule is transferred to the perfusion apparatus which utilizes two sets of pipettes: one for perfusion via the afferent arteriole as well as measurement of glomerular hydrostatic pressure and, the second, for the collection of fluid from the efferent arteriole. With this technique one can measure PGC, Pi GC, SNGFR, QA and filtration fraction and one can calculate KF.