交感神经抑制在溴隐亭对正常血压和高血压大鼠血管减压作用中的作用。

Role of sympathetic nerve inhibition in the vasodepressor effect of bromocriptine in normotensive and hypertensive rats.

作者信息

Oguro M, Takeda K, Itoh H, Takesako T, Tanaka M, Takenaka K, Hirata M, Nakata T, Tanabe S, Hayashi J

机构信息

Second Department of Medicine, Kyoto Prefectural University of Medicine, Japan.

出版信息

Jpn Circ J. 1992 Sep;56(9):943-9. doi: 10.1253/jcj.56.943.

DOI:10.1253/jcj.56.943

PMID:1404848

Abstract

This study aimed to elucidate the mechanism of the hypotensive effect of bromocriptine (BRC), and to investigate whether or not the effects of BRC on the sympathetic nervous system are altered in hypertension. BRC was administered intravenously to normotensive and spontaneously hypertensive rats (SHR). It elicited hypotensive effects dose-dependently in urethane-anaesthetized normotensive rats, an effect which was antagonized with metoclopramide. Pretreatment with intravenous hexamethonium attenuated the hypotensive effect of BRC. BRC decreased plasma norepinephrine (NE) without inhibiting the sympathetic nerve spikes recorded from the postganglionic sympathetic nerve bundle. The hypotensive effect of BRC was significantly greater in SHR than in Wistar Kyoto Rats (WKY). Decrease in NE by BRC was also significantly greater in SHR than in WKY. These results suggest that the hypotensive effect of BRC is induced by suppression of NE release, not by inhibition of sympathetic nerve spikes, and that the dopaminergic presynaptic inhibition is attenuated in SHR.

摘要

本研究旨在阐明溴隐亭（BRC）降压作用的机制，并研究高血压状态下BRC对交感神经系统的作用是否发生改变。将BRC静脉注射到正常血压大鼠和自发性高血压大鼠（SHR）体内。在乌拉坦麻醉的正常血压大鼠中，BRC呈剂量依赖性地引发降压作用，该作用可被甲氧氯普胺拮抗。静脉注射六甲铵预处理可减弱BRC的降压作用。BRC可降低血浆去甲肾上腺素（NE）水平，但不抑制节后交感神经束记录到的交感神经冲动。BRC对SHR的降压作用明显强于Wistar Kyoto大鼠（WKY）。BRC使SHR的NE降低幅度也明显大于WKY。这些结果表明，BRC的降压作用是由抑制NE释放而非抑制交感神经冲动诱导的，并且SHR中多巴胺能突触前抑制作用减弱。