Influence of age on steroid concentrations in skin and striated muscle in women and in cardiac muscle and lung tissue in men.

In order to investigate whether androgen concentrations vary as a function of age in all tissues and organs and whether the sexual differences in plasma androgen levels are reflected in tissue concentrations, testosterone (T), 5 alpha-androstane-17 beta-ol, 3-one (DHT), 5 alpha-androstane-3 alpha,17 beta-diol (Adiol), and 4-androstene-3,17-dione (Adion) concentrations were measured postmortem in lung tissue and myocardium of men aged 16-87 yr. The results were compared to values obtained previously in other tissues. Similar measurements were made in various tissues (labia majora, clitoris, pubic skin, thigh skin, striated muscle) from women aged 16-87 yr. In cardiac tissue of men, T was quantitatively the most important androgen and concentrations of DHT and Adiol were low, reflecting low 5 alpha-reductase activity; in lung tissue, T and Adion were found in similar concentrations, with lower levels of 5 alpha-reduced metabolites. In both cardiac and lung tissue, androgen concentrations decreased significantly with age. In women, androgen concentrations were highest in specific androgen target tissues (labia majora, clitoris) and lowest in thigh skin and striated muscle. The ratios of the 5 alpha-saturated metabolites (DHT plus Adiol) to T or to T + Adion, respectively, parallel total androgen concentrations, whereas the Adiol to DHT ratio, a parameter of 3 alpha-reductase activity, was highest in striated muscle and thigh skin and lowest in androgen target tissues (labia majora and clitoris). In women tissue concentrations of all androgens decreased significantly with age in nearly all tissues studied. As expected tissue androgen concentrations were lower in women than in men, but in androgen target tissues such as the clitoris or labia majora, concentrations were little lower than in scrotal skin. We conclude that in both men and women androgen target tissues contain high androgen concentrations and high 5 alpha-reductase activity; moreover androgen concentrations in target tissues are similar in both sexes. In both sexes tissue androgen concentrations decreased with age in most tissues, but in target tissues the decrease was more pronounced in women than in men.