Yorihisa Mitani

The Effects of Synthetic α-Human Atrial Natriuretic Peptide (α-hANP) on the Overall Baroreflex System in Anesthetized Mongrel Dogs

The effects of α-hANP (0.3 μg/kg body weight/min) on the baroreflex system were studied in anesthetized dogs according to three different protocols. In the first protocol, the effects of α-hANP on an open-loop gain (GAP) of the overall baroreflex system and a gain (GHR) of the baroreflex heart rate control system during quick mild hemorrhage and blood infusion were studied. GAP was decreased from 7.6 ± 0.6 to 2.8 ± 0.5 by α-hANP with hemorrhage. GAP decreased 7.4 ± 0.8 to 2.9 ± 0.4 by α-hANP with blood infusion. GAP was restored nearly to the control levels one hour after α-hANP administration. GHR did not change by α-hANP administration. In the second and third protocol, a site of action of α-hANP was analysed. α-hANP inhibited the responses of systemic vascular resistance to quick mild hemorrhage and blood infusion, but did not affect the responses of cardiac output to quick mild hemorrhage and blood infusion in the second protocol. After carotid sinus denervation and vagotomy. α-hANP inhibited an arter...