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 th e reproductively active prespawning phase (June) of its annual reprodu ctive 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) o f gamma-hexachlorocyclohexane (gamma-HCH) in the presence of either ex ogenous precursor [H-3]-17-hydroxyprogesterone ([H-3]17-P) or carp hyp ophyseal homogenate. The free (unconjugated) and conjugated metabolite s (glucuronides and sulfates) of [H-3]-17-P [androstenedione (AD), and rostenetrione, 17-hydroxyprogesterone, testosterone (T), 11-deoxycorti sol (S), 17,20 alpha-dihydroxy-4-pregnen-3-one (17,20 alpha P), 17,20 beta-dihydroxy-4-pregnen-3-one (17,20 beta P), 7 alpha-pregnanetetrols (7 alpha-P), and other polar metabolites] were separated by thin-laye r chromatography and high-performance liquid chromatography. The endog enous production of unconjugated (free) steroids T, 17,20 alpha P, S, and 11-ketotestosterone (11-KT) in response to gamma-HCH were measured by radioimmunoassay. Among the in vitro metabolism of [H-3]-17-P, in males, free steroids of AD, T, 17,20 alpha P, S, and polar-free steroi ds 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 17,20 alpha P, 17,20 beta P, S, and 11-KT remain unchanged. In fema les, the decreased percentage of yield of AD and S and elevated T were noticed. The yield of TG was increased with decreased yield of 7 alph a-P glucuronides. The percentage yield of AD sulfate and sulfate stero ids of 17,20 alpha P, 17,20 beta P, 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. 17,20 beta P was stimulated at s ome concentrations in both sexes but levels were very low. Results ind icate that gamma-HCH in vitro perturbed the steroid biosynthesis durin g this phase thereby affecting reproductive physiology. (C) 1996 Acade mic Press, Inc.