Changes in the mechanisms of steroid action during aging

This paper reviews some representative changes in steroid action and hormone receptors as a function of age. In many of the cases studied, receptor concentrations (but not affinity) were found to decrease during aging. These investigations employed various cells and tissues from humans and animals. Loss of receptors is closely correlated with decline in particular biological responses in a number of studies. Moreover, loss of glucocorticoid receptors seems to occur in individual cells (rather than by a simple loss of receptor containing cells from complex tissues) when denned post-mitotic cell populations have been investigated. Therefore, it appears that reductions in various steroid receptor concentrations in targets cells are closely, if not casually, related to decreased biological responsiveness during senescence. Possible mechanisms of steroid receptor change during aging are suggested and discussed.