Effects of ketanserin on cardiovascular, sympatho-adrenal and endocrine systems during physical exercise in man

Blood pressure, heart rate, oxygen consumption, plasma concentrations of catecholamines, renin, aldosterone and lactate were measured in 6 normotensive volunteers during a randomized cross-over study of oral ketanserin (20 mg X 7) and placebo; measurements were made at rest and during maximal dynamic exercise on a bicycle ergometer. At rest ketanserin reduced blood pressure without modifying heart rate or plasma noradrenaline and adrenaline. Duration of exercise and blood lactate levels did not differ between the ketanserin and the control group. During exercise only systolic blood pressure was significantly decreased on ketanserin at maximal work rate whereas heart rate did not change. Plasma noradrenaline was significantly increased and plasma aldosterone significantly decreased during exercise in ketanserin-treated subjects whereas plasma renin activity and plasma adrenaline remained unchanged. Finally, under ketanserin oxygen consumption during exercise was reduced. The results suggest that ketanserin might interfere with the sympathetic nervous system and aldosterone secretion in man.