Hemodynamic Alterations Following Infusion of Angiotensin II Analogue in Normal Subjects

Changes of blood pressure (BP), creatinine clearance (Ccreat), plasma renin activity (PRA), plasma aldosterone concentration (PAC) and urinary excretion of adrenaline and noradrenaline (uAD, uNAD) were studied in 5 normal subjects following i. v. infusion of 1-sarcosine, 8-isoleucine angiotensin II (sar1, ile8-A II) and angiotensin II (A II). The effects of variable sodium balance on these changes were studied as well. Sar1, ile8-A II demonstrated variable agonistic activities at 4 sites of A II action, i.e., Ccreat, PRA and PAC. There seemed to be a reciprocal relation between agonistic and antagonistic activities (latter being evaluated by antagonism against A II-induced changes of BP, Ccreat, PRA and PAC) of sar1, ile8-A II at each of sites, which would rather suggest similarity than heterogeneity of A II receptors at these sites. It was disclosed that agonistis activities on BP, PRA and PAC were dependent on sodium balance, i.e., most agonistic during sodium repletion and least active during sodium depletion. The implications of these findings were discussed.