Plasma hormonal levels after castration and hormonal replacement. (A) Castration resulted in a significant reduction of 93% in the serum testosterone concentration. Corn oil, estradiol (E2) and 3β-diol maintained the testosterone level similar to castrated rat, while DHT increased the plasma testosterone concentration. (B) The plasma estradiol concentration was not affected by the castration or replacement with corn oil, DHT and 3β-diol. However, after estradiol replacement, a significant increase in the plasma estradiol level was observed. Values represent mean ± SEM; n = 5 in each group; (*) = P ≤ 0,05 when compared to control group; (‡) = P ≤ 0,05 when compared to castrated group.