ANDROGEN METABOLISM IN THE DIFFERENT LOBES OF THE PROSTATE-GLAND OF INTACT, GONADECTOMIZED OR HYPOPHYSECTOMIZED RATS WITH OR WITHOUT ANDROGEN SUBSTITUTION

The effect of gonadectomy or hypophysectomy and the effect of substitu tion with testosterone, upon the reductive and oxidative metabolic tra nsformations of testosterone, 4-androstene-3,17-dione, 17beta-hydroxy- 5alpha-androstane-3-one, 5alpha-androstane-3alpha,17beta-diol and 5alp ha-androstane-3beta,17beta-diol using NAD(H) and NADP(H) as added cofa ctors were examined in homogenates from the ventral, (VP), lateral (LP ) and dorsal prostate (DP), and coagulating gland (CG) of adult Wistar rats. The fall in serum testosterone induced by gonadectomy or hypoph ysectomy led to reduced activity of 5alpha-reductase, NADP(H)-dependen t 3alpha-hydroxysteroid oxidoreductase (3alpha-HSOR), NAD-dependent 3a lpha-HSOR, 3beta-HSOR and 17beta-HSOR, indicating that these enzymes a re androgen dependent. The NADP dependent oxidation of 5alpha-androsta ne-3alpha,17beta-diol in LP increased upon hypophysectomy and gonadect omy. Testosterone substitution of gonadectomized or hypophysectomized rats generally maintained enzymatic activity at the level of the contr ol group, except for the 5alpha-reductase activity which fell in spite of this treatment. Hypophysectomy or gonadectomy had different effect s on the activity of several androgen metabolizing enzymes; 5alpha-red uctase activity in DP and CG, NAD(H) dependent 3alpha-HSOR in VP and N ADPH dependent 3beta-HSOR activity in LP, DP and CG. There were marked differences between the rat prostatic lobes, both concerning the acti vity of the androgen metabolizing enzymes and the responses to the dif ferent treatment modalities.