臓器循環に関する研究 ： ANP投与が諸臓器循環動態におよぼす影響

Abstract

A study was perfomed on anesthetized dogs to determine the effects of three doses of synthetic atrial natriuretic peptide (ANP) on systemic and regional hemodynamics. ANP produced falls in mean aortic blood pressure for all doses : 0.1 μg・kg⁻¹(low dose), 0.5 μg・kg⁻¹(medium dose), and 2.5 μg・kg⁻¹(high dose). With medium and high doses, a transient decrease in total peripheral resistance and a similar increase in cardiac output (CO) were observed the stage immediately following administration of ANP. Marked but transient increases in carotid blood flow was observed after administration of all three doses of ANP. Furthermore, ANP caused transient decreases in carotid vascular resistance, while carotid blood flow increased more markedly than CO. On the other hand, organ blood flow to the splanchnic organs and skeletal muscles decreased or tended to decrease. This study demonstrates that (1) ANP mediated reduction in aortic blood pressure creates a decrease in total peripheral resistance, (2) ANP most effectively relaxes the carotid artery, and (3) the hepatic, mesenteric and femoral arteries are less sensitive to ANP.