Estrogen receptor specificity in the regulation of skeletal growth and maturation in male mice

Androgens may regulate the male skeleton directly through a stimulation of androgen receptors or indirectly through aromatization of androgens into es trogen and, thereafter, through stimulation of estrogen receptors (ERs). Th e relative importance of ER subtypes in the regulation of the male skeleton was studied in ER alpha-knockout (ERKO), ER beta-knockout (BERKO) and doub le ER alpha/beta-knockout (DERKO) mice. ERKO and DERKO, but not BERKO, demo nstrated decreased longitudinal as well as radial skeletal growth associate d with de creased serum levels of insulin-like growth factor I. Therefore, ER alpha, but not ER beta, mediates important effects of estrogen in the sk eleton of male mice during growth and maturation.