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 estrogen and, thereafter, through stimulation of estrogen receptors (ERs). The relative importance of ER subtypes in the regulation of the male skeleton was studied in ER alpha-knockout (ERKO), ER beta-knockout (BERKO) and double ER alpha/beta-knockout (DERKO) mice. ERKO and DERKO, but not BERKO, demonstrated decreased longitudinal as well as radial skeletal growth associated 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 skeleton of male mice during growth and maturation.