Abstract
Abstract
Many responses to hormones are altered during aging. Almost all the cellular components involved in mediating hormone actions have, in one situation or another, been implicated in such responsiveness changes. Glucocorticoid inhibition of glucose oxidation in rat adipocytes and catecholamine stimulation of rat heart contractile performance are two examples of reduced hormonal responsiveness during aging. In the former system, age changes have been reported in glucocorticoid receptor concentrations, rates of putative receptor biosynthesis, regulation of the glucose transport system, and the sulfhydryl content of the plasma membrane. In the latter system, no changes have been observed in catecholamine receptors, cyclic AMP production, or protein kinase activation. Instead, the age-associated functional change appears to be related to control of calcium entry into the cell. The manifestations of aging at the level of hormone action, therefore, appear to be multifaceted.
Get full access to this article
View all access options for this article.