Abstract

1. The response of systemic and regional haemodynamic indices to increasing infusion rates of angiotensin II (1, 3 or 10 ng min-1 kg-1) or placebo [5% (w/v) D-glucose] was studied in eight normal male subjects. 2. As compared with placebo, angiotensin II infusion caused an incremental rise in the serum angiotensin II level [14.5 +/- 7.7 (placebo) to 187.2 +/- 36.1 (10 ng of angiotensin II min-1 kg-1) pmol/l; mean +/- 95% confidence interval] associated with a stepwise increase in total peripheral resistance [880 +/- 42 (placebo) to 1284 +/- 58 (10 ng of angiotensin II min-1 kg-1) dyn s cm-5] and a progressive reduction in cardiac output [8.3 +/- 0.4 (placebo) to 7.0 +/- 0.4 (10 ng of angiotensin II min-1 kg-1) litres/min]. 3. A stepwise fall in renal blood flow was observed with increasing angiotensin II infusion rate [1302 +/- 65 (placebo) to 913 +/- 64 (10 ng of angiotensin II min-1 kg-1) ml/min]. In contrast, calf blood flow was unaffected by 1 ng or 3 ng of angiotensin II min-1 kg-1 and was significantly increased by 10 ng of angiotensin II min-1 kg-1 (P less than 0.01). 4. Calf venous capacitance was uninfluenced by 1 ng of angiotensin II min-1 kg-1, but was significantly increased by both 3 ng (P less than 0.005) and 10 ng (P less than 0.001) of angiotensin II min-1 kg-1.(ABSTRACT TRUNCATED AT 250 WORDS)