This is a program project including an integrated series of basic science and clinical investigations into the cell biology and physiology of aging. Cell biology studies include materials from aging rodents and man and focus on 1) the relation of aging and ultraviolet light to changes in cell growth in vitro, 2) the influence of age on capacity of the cell to serve as host for herpes virus infection, and 3) the influence of age on smooth muscle cell proliferation in the arterial wall after injury. The clinical physiologic studies include investigations of the effect of age on 1) the metabolism and secretion of arginine vasopressin, 2) the inter-relation of the sympathetic nervous system and carbohydrate tolerance, and 3) the inter-relation between salt balance and prostaglandin physiology.