Evidence for the involvement of different receptor subtypes in the pre- and postjunctional actions of angiotensin II at rat sympathetic neuroeffector sites.

Abstract

1. The effects of the nonpeptide angiotensin II receptor (AT) antagonists losartan and PD 123319 on actions of angiotensin II in the rat caudal artery and rat vas deferens preparations were investigated. 2. Angiotensin II (1.0 microM) increased perfusion pressure in isolated segments of the rat caudal artery. This increase in perfusion pressure was prevented by the AT1-antagonist, losartan (0.1 microM) but was not affected by the AT2-antagonist, PD 123319 (0.1 microM). 3. Angiotensin II (0.1-3.0 microM) produced a concentration-dependent enhancement of the stimulation-induced (S-I) efflux of [3H]-noradrenaline from isolated segments of rat caudal artery in which the noradrenergic transmitter..