In vitro effects of gamma-hexachlorocyclohexane on in vitro biosynthesis and metabolism of steroids in goldfish Carassius auratus.

Testicular and ovarian fragments of Carassius auratus, taken during the reproductively active prespawning phase (June) of its annual reproductive cycle, were incubated with different concentrations (0 mg/ml, 0 ppm; 0.001 mg/ml, 1 ppm; 0.01 mg/ml, 10 ppm; and 0.02 mg/ml, 20 ppm) of gamma-hexachlorocyclohexane (gamma-HCH) in the presence of either exogenous precursor [3H]-17-hydroxyprogesterone ([3H]17-P) or carp hypophyseal homogenate. The free (unconjugated) and conjugated metabolites (glucuronides and sulfates) of [3H]-17-P [androstenedione (AD), androstenetrione, 17-hydroxyprogesterone, testosterone (T), 11-deoxycortisol (S), 17, 20alpha-dihydroxy-4-pregnen-3-one (17,20alphaP), 17, 20beta-dihydroxy-4-pregnen-3-one (17,20betaP), 7alpha-pregnanetetrols (7alpha-P), and other polar metabolites] were separated by thin-layer chromatography and high-performance liquid chromatography. The endogenous production of unconjugated (free) steroids T, 17,20betaP, S, and 11-ketotestosterone (11-KT) in response to gamma-HCH were measured by radioimmunoassay. Among the in vitro metabolism of [3H]-17-P, in males, free steroids of AD, T, 17,20alphaP, S, and polar-free steroids were increased with the decreased yield of 11-KT. Percentage yield of testosterone glucuronide (TG) was increased with highly significant decreased yields of polar glucuronide steroids. The sulfate steroids of 17, 20alphaP, 17,20betaP, S, and 11-KT remain unchanged. In females, the decreased percentage of yield of AD and S and elevated T were noticed. The yield of TG was increased with decreased yield of 7alpha-P glucuronides. The percentage yield of AD sulfate and sulfate steroids of 17,20alphaP, 17,20betaP, and S were noted to be increased, but the yield for S sulfate was very high. Endogenous production of T was increased in both sexes in the presence of gamma-HCH, but 11-KT in male and S in female were depressed. 17, 20betaP was stimulated at some concentrations in both sexes but levels were very low. Results indicate that gamma-HCH in vitro perturbed the steroid biosynthesis during this phase thereby affecting reproductive physiology.