Forearm Venous Responses to Stimulation of Adrenergic Receptors.

The properties of the adrenergic receptors in the veins or capacitance vessels of man have not been defined completely. Norepinephrine causes constriction of resistance vessels by stimulation of alpha receptors (2); it also causes constriction of the veins or capacitance vessels (3-5). Isoproterenol causes dilatation of resistance vessels by stimulation of beta receptors (6), but reports of its action on the capacitance vessels are conflicting. It appears to cause forearm venous constriction when administered systemically (7), but dilatation is said to occur with infusion into the brachial artery (8). The experiments to be reported here were done to investigate the effects of stimulation of alpha and beta receptors in the veins of the forearm of man in a systematic fashion.