UP-REGULATION OF ANDROGEN RECEPTOR IMMUNOREACTIVITY IN THE RAT-BRAIN BY ANDROGENIC-ANABOLIC STEROIDS

To characterize central nervous system changes that occur with anaboli c steroid abuse in humans, immunocytochemical localization of androgen receptors in the brains of 10 intact and 10 castrated male rats was c onducted after the administration of high levels of androgenic-anaboli c steroids (AAS; 14 daily injections of sesame oil or a cocktail of 2 mg/kg testosterone cypionate, 2 mg/kg nandrolone decanoate, and 1 mg/k g boldenone undecylenate). In normal intact oil-treated males, nuclear androgen receptor immunoreactivity was present in many 'classical' an d 'non-classical' androgen target sites in the brain. Administration o f AAS increased the intensity of immunoreactivity in most classical an drogen target sites and increased both the intensity of immunoreactivi ty and number of immunoreactive cells in most non-classical androgen t arget sites. These results may suggest that androgen receptors in the brain are up-regulated by AAS. The simultaneous androgen receptor up-r egulation in these regions by AAS may account for the complex anabolic steroid abuse syndrome. Consistently, androgen receptor immunoreactiv ity in most brain regions was reduced or absent after castration, sugg esting that endogenous androgen levels are necessary for normal androg en receptor immunoreactivity. These results identify the distribution of one central nervous system mechanism modified by AAS.