Androgen receptor the development and maintenance of the male sexual phenotype. In some cell types, testosterone interacts directly with androgen receptors, whereas, in others, testosterone is converted by 5-alpha-reductase to dihydrotestosterone, an even more potent agonist for androgen receptor activation. Testosterone appears to be the primary androgen receptor-activating hormone in the Wolffian duct, whereas dihydrotestosterone is the main androgenic hormone in the urogenital sinus, urogenital tubercle, and hair follicles. Hence, testosterone is responsible primarily for the development of male primary sexual characteristics, whereas dihydrotestosterone is responsible for secondary male characteristics. Androgens cause slow epiphysis, or maturation of the bones, but more of
Growth hormone–releasing hormone Growth hormone–releasing hormone Growth hormone–releasing hormone (GHRH), also known as somatocrinin or by several other names in its endogenous forms and as somatorelin (INN) in its pharmaceutical form, is a releasing hormone of growth hormone (GH). It is a 44-amino acid peptide hormone produced in the arcuate nucleus of the hypothalamus. GHRH first appears in the human hypothalamus between 18 and 29 weeks of gestation, which corresponds to the start of production of growth hormone and other somatotropes in fetuses. GHRH is released from neurosecretory nerve terminals of these arcuate neurons, and is carried by the hypothalamo-hypophyseal portal system to