Forearm and calf blood flow in response to cortical arousal in normal male and female subjects.

The aim of this study was to investigate cardiovascular changes, particularly in forearm and calf blood flows, in response to acute emotional stress in men and women. The study was approved by the Ethics Committee of the Queen's Medical Centre, Nottingham University. Fifty-six healthy non-smokers (29 men and 27 women) aged 19 to 22 years participated. Blood flow was measured by venous occlusion plethysmography using mercury-in-silastic strain gauges. Acute emotional stress (2 min) was elicited by a visual orientation task. During acute emotional stress, there were increases in heart rate (males = 40 +/- 3%, females = 49 +/- 5%) and mean arterial pressure (males = 24 +/- 2%, females = 22 +/- 2%), and hyperaemia and vasodilatation were observed in the forearm (males = 162 +/- 15%, females = 239 +/- 31%) and calf (males = 78 +/- 16%, females = 131 +/- 24%). Vasoconstriction also occurred in some subjects. Forearm vasodilatation was significantly greater than calf vasodilatation. Gender variation was apparent in the calf, where vasodilatation was significantly greater in females, and vasoconstriction was significantly greater in males. In some subgroups of men and women, mean values indicated that acute emotional stress elicited increases in forearm, but not in calf, blood flows and vascular conductances. This pattern is similar to that reported by Rusch et al. (see text), but the present findings indicate that vasodilatation in the forearm and calf in response to acute emotional stress is more common.