The pressor effect of exogenous angiotensin II is diminished during dynamic exercise.
To evaluate the effect of dynamic exercise on the response to angiotensin II (AII), AII (7.5 ng/kg/min) or vehicle (P) was infused intravenously in seven normal sodium replete volunteers before, during and after a graded uninterrupted exercise test until exhaustion, using a randomized cross-over protocol. Plasma angiotensin II (PAII) during AII infusion was an average 86-145 pg/ml higher than during P. The differences in mean intra-arterial pressure between the AII and the P tests averaged 17 mmHg at recumbent rest, 12 mmHg in the sitting position on the bicycle ergometer and 7 mmHg at 20% of peak work rate declining progressively throughout the exercise test to become insignificant from 80% of peak work rate on. A significant difference reappeared after exercise. It is suggested that the powerful vasoconstriction in some vascular beds and the dilatation in others oppose the vasoconstricting effect of AII; other possible mechanisms are changes in pH and a decrease of the difference in log PAII between the AII and P tests with increasing levels of endogenous PAII during exercise.
D000138:Acidosis / Q000097:blood; D000328:Adult; D000804:Angiotensin II / Q000097:blood / Q000494:pharmacology*; D001769:Blood; D001794:Blood Pressure / Q000187:drug effects*; D006801:Humans; D006863:Hydrogen-Ion Concentration; D008297:Male; D005082:Physical Exertion; D012016:Reference Values; D012146:Rest
D000804:Angiotensin II