Abstract
Cardiovascular responsiveness to stress conditions differs between men and women. It is not known to what extent this observation is explained by differences in the release of stress hormones like adrenaline, or by differences in the response to adrenaline. Therefore, we quantified the hemodynamic response to infusion of adrenaline (0.04, 0.06, and 0.08 microg x kg(-1) x min(-1) for 20 minutes each) in 8 healthy men and 8 healthy premenopausal women. Arterial plasma adrenaline levels were measured before and after infusion. Heart rate and intra-arterial blood pressure were monitored throughout the experiment. Arterial plasma adrenaline levels increased similarly in both sexes. There was a larger increase in systolic blood pressure in women compared with men (17.6 +/- 2.8 versus 5.1 +/- 3.1 mm Hg, P < 0.01). In contrast, men showed a larger increase in heart rate compared with women (20.3 +/- 1.4 versus 11.2 +/- 2.8 bpm, P < 0.01). In conclusion, these data suggest that the cardiovascular response to adrenaline is predominantly alpha-adrenergic in premenopausal women, and predominantly beta-adrenergic in age-matched men.
