CORTICOSTEROID RECEPTORS AND AGING

We have measured plasma aldosterone, plasma cortisol, and glucocorticoid and mineralocorticoid receptors in mononuclear leukocytes in 54 healthy aged subjects (60-97 years old) and in a group of 21 controls (21-50 years old). In addition all parameters and age were plotted for correlation. Plasma cortisol was significantly higher in the aged group (346 +/- 140 nmol/l) than in controls (260 + 120). Mean plasma aldosterone was not different in the two groups. Both Type I and II receptors in mononuclear leukocytes were lower in the aged group than in controls (Type I 198 +/- 96 and 272 +/- 97 receptors per cell; Type II 1738 +/- 801 and 3339 +/- 918 receptors per cell). A direct correlation was found between cortisol and age and between Type I and II receptors in aged subjects, and between cortisol and Type I receptors, and cortisol and Type II receptors in controls. When all subjects are plotted together, a direct correlation was observed between cortisol and age and between Type I and II receptors, and an inverse correlation between age and Type I and age and Type II receptors. We conclude that the parallel reduction of both Type I and II receptors with age is not due to prior cortisol increase, but the increase of plasma cortisol can be considered the result of age-dependent involution of these receptors.