In Vitro Effects of γ-Hexachlorocyclohexane on Biosynthesis and Metabolism of Steroids in Goldflsh Carassius auratus (L.)

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,0.001 mg/ml, lppm;0.01 mg/ml, 10ppm; and 0.02 mg/ml, 20 ppm) of γ-hexachlorocyclohexane (γ-HCH) in the presence of either exogenous precursor [³H]-17-hydroxyprogesterone ([³H]-17-P 96.5kBq, 13.04ng/Incubation) or carp hypophyseal homogenate (chh, 100 μγg/incubation). The free (unconjugated) and conjugated metabolites (glucuronides and sulfates) of [³H]-17-P [androstenedione (AD), androstenetrione, 17-hydroxyprogeste-rone, testosterone (T), 11- deoxycortisol (S), 17, 20α-dihydroxy-4-pregnen-3-one (17,20αP), 17,20β-dihydroxy-4-pregnen-3-one (17, 20βP), 7α-pregnanetetrols (7α-P), and other polar metabolites] were separated by thin layer chromatography and high performance liquid chromatography. The endogenous production of unconjugated (free) steroids T, 17,20βP, S and 11-ketotestosterone (11-KT) in response to γ-HCH were measured by radioimmunoassay. Among the in vitro metabolism of [³]-17-P, in males; free steroids of AD, T, 17,20aP, 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, 20αP, 17, 20βP, 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 7α-P glucuronides. The percentage yield of AD sulfate and sulfate steroids of 17, 20αP, 17, 20βP 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 γ-HCH, but 11-KT in male and S in female were depressed. 17,20βP was stimulated at some concentrations in both sexes but levels were very low. Results indicate that γ-HCH in vitro perturbed the steroids biosynthesis during this phase thereby affecting reproductive physiology.