Hazon N, Balment R J, Perrott M, O'Toole L B
Department of Biology and Preclinical Medicine, Gatty Marine Laboratory, University of St. Andrews, United Kingdom.
Gen Comp Endocrinol. 1989 May;74(2):230-6. doi: 10.1016/0016-6480(89)90217-7.
The role of a renin-angiotensin-like system (RAS) in the regulation of blood pressure and drinking has been investigated in the elasmobranch, Scyliorhinus canicula. Injection of exogenous angiotensin II produced, as expected, a vasopressor response, though injection of the converting enzyme inhibitor, Captopril, alone produced little change in resting blood pressure. Papaverine, a smooth muscle relaxant, reduced blood pressure which completely recovered within 30 min. A subsequent injection of Captopril produced a rapid vasodepressor response with no recovery over 2 hr. The low basal levels of drinking in dogfish were not altered by Captopril injection but angiotensin II-induced increased drinking and papaverine administration resulted in markedly stimulated water intake, which was inhibited by coadministration with Captopril. Captopril inhibition of the recovery in blood pressure and associated dipsogenic response following the papaverine-induced hypotension is consistent with the activation of a RAS-like system in the dogfish. This and other evidence supporting the presence of a RAS-like system in elasmobranchs are discussed in relation to other vertebrates.
肾素 - 血管紧张素样系统（RAS）在调节血压和饮水方面的作用已在板鳃亚纲鱼类小斑猫鲨（Scyliorhinus canicula）中得到研究。正如预期的那样，注射外源性血管紧张素II会产生升压反应，不过单独注射转化酶抑制剂卡托普利对静息血压几乎没有影响。平滑肌松弛剂罂粟碱可降低血压，血压在30分钟内完全恢复。随后注射卡托普利会产生快速的降压反应，2小时内血压未恢复。注射卡托普利不会改变角鲨的低基础饮水水平，但血管紧张素II诱导的饮水增加以及给予罂粟碱会导致明显的饮水刺激，而与卡托普利共同给药会抑制这种刺激。卡托普利抑制罂粟碱诱导的低血压后血压的恢复以及相关的致渴反应，这与角鲨中类似RAS系统的激活是一致的。本文结合其他脊椎动物讨论了这一现象以及支持板鳃亚纲鱼类中存在类似RAS系统的其他证据。
