α₁遮断薬Prazosinと腎循環

Abstract

The hemodynamic properties of prazosin (Pz), a selective α₁-receptor blocking agent, were examined. To investigate the effects of Pz on systemic and renal hemodynamics in anesthetized adult mongrel dogs, cardiac output (CO), renal blood flow (RBF) and renal cortical blood flow (CBF) were observed using an electromagnetic flowmeter and the electrolytic hydrogen clearance method. RBF and CBF through the extracorporeal circuit with fixed perfusion pressure (100 mmHg) were also measured. When Pz was administered intravenously at a low (0.005 mg/kg), medium (0.05 mg/kg), or high dose (0.5 mg/kg) : 1) aortic blood pressure (ABP) was reduced ; 2) CO was increased early and decreased subsequently ; 3) RBF, CBF, effective renal blood flow (ERBF) and glomerular filtration rate (GFR) were decreased at the high dose, but were increased in the extracorporeal circuit. α₁-receptor blocking agents are recognized to have little adverse effect on RBF and renal function, although when high doses are used, these parameters may be reduced.