Blair M L, Reid I A, Ganong W F
J Pharmacol Exp Ther. 1977 Jul;202(1):209-15.
The aim of the present study was to investigate the possibility that catecholaminergic pathways within the central nervous system play a role in the control of renin secretion. Plasma renin activity (PRA) was measured after intravenous administration of L-dopa with and without prior inhibition of extracerebral dopa decarboxylase by carbidopa (MK-486) in pentobarbital-anesthetized dogs in which changes in renal perfusion pressure were minimized by means of a suprarenal aortic clamp. When L-dopa (20 mg/kg ) was administered intravenously without carbidopa. PRA and blood pressure increased. In contrast, administration of L-dopa (20 mg/kg i.v.) after blockade of extracerebral, but not cerebral dopa decarboxylase by intravenous carbidopa (20 mg/kg), produced significant decrease in both PRA and blood pressure. Larger doses of l-dopa (30-50) mg/kg i.v.) also lowered both PRA and blood presure in three carbidopa-treated animals, whereas a smaller dose of L-dopa (10 mg/kg i.v.) significantly lowered blood pressure but not PRA. In dogs with both kidneys acutely denervated, L-dopa (20 mg/kg i.v.) with carbidopa lowered arterial pressure but did not consistently alter PRA. These data suggest that catecholamines formed within the central nervous system can act to lower renin secretion as well as blood pressure.
本研究的目的是探讨中枢神经系统内的儿茶酚胺能途径在肾素分泌控制中发挥作用的可能性。在戊巴比妥麻醉的犬中，通过肾上腺上主动脉夹将肾灌注压的变化降至最低，静脉注射左旋多巴（L-dopa），在有和没有事先用卡比多巴（MK-486）抑制脑外多巴脱羧酶的情况下，测量血浆肾素活性（PRA）。当静脉注射左旋多巴（20mg/kg）而不使用卡比多巴时，PRA和血压升高。相反，在静脉注射卡比多巴（20mg/kg）阻断脑外而非脑内多巴脱羧酶后，静脉注射左旋多巴（20mg/kg）会使PRA和血压显著降低。在三只接受卡比多巴治疗的动物中，较大剂量的左旋多巴（30 - 50mg/kg静脉注射）也降低了PRA和血压，而较小剂量的左旋多巴（10mg/kg静脉注射）显著降低了血压，但未降低PRA。在双侧肾脏急性去神经支配的犬中，左旋多巴（20mg/kg静脉注射）加卡比多巴降低了动脉血压，但并未持续改变PRA。这些数据表明，中枢神经系统内形成的儿茶酚胺可降低肾素分泌以及血压。
