beta-Adrenoceptor-mediated functions appear to diminish with aging, but the exact scope of these changes is unknown, because most studies have been limited to beta 1-adrenergic cardiac phenomena. To evaluate both a vascular and a nonvascular beta 2-adrenergic response in the aged, we have studied 12 healthy elderly and 12 healthy young subjects infused with increasing doses of isoproterenol and compared the change in peripheral vascular resistance, measured by venous occlusion plethysmography, and insulin release. In both groups vascular resistance fell and insulin concentrations increased. These changes were equivalent in both groups, and we therefore infer no significant decline in either of these beta 2-adrenergic functions in the elderly.