Further studies on the effects of heroin addiction on the hypothalamic-pituitary-gonadal function in man.

The effects of chronic heroin addiction on LH biological and immunological activity, as well as on total and free testosterone concentrations, were investigated in 8 active young male addicts. The results were compared with those obtained in 33 normal young men. In addition, the effects of naloxone (N) administration on LH bio- and immuno-potency were studied in 3 normal men. LH biological activity (bLH) was assessed by a specific and sensitive "in vitro" bioassay, based upon testosterone production by mechanically dispersed mouse Leydig cell preparations. Double antibody radioimmunoassay methods were employed to assess serum levels of immunoreactive LH (iLH), total testosterone (T) and morphine (M). Free testosterone (FT) concentrations were determined by RIA after an ultrafiltration procedure. Mean basal values of bLH, iLH, T and LH bio/immuno (b/i) ratio observed in heroin addicts were similar to those obtained in the control group. In contrast, serum levels of FT and the mean FT/T ratio were significantly reduced in heroin addicts. A significant decrease of LH b/i ratio was observed during N infusion in the normal subjects.