IMPACT OF GAMMA-HEXACHLOROCYCLOHEXANE ON THE IN-VITRO PRODUCTION OF STEROIDS FROM ENDOGENOUS AND EXOGENOUS PRECURSORS IN THE SPERMIATING ROACH, RUTILUS-RUTILUS

Testicular fragments from spermiating roach were incubated with 0, 1, 10 and 20 mg/L of gamma-hexachlorocyclohexane (gamma-HCH), and either carp hypophyseal homogenate (chh) or H-3-17-hydroxyprogesterone (H-3-1 7P). The endogenous production of testosterone (T), 17-hydroxyprogeste rone (17P), 17,20 beta-dihydroxy-4-pregnen-3-one (17,20 beta P), 11-ke totestosterone (KT), testosterone glucuronide (TG), and 17,20 beta-dih ydroxy-4-pregnen-3-one glucuronide (17,20 beta PG) was measured by rad ioimmunoassay. The effect of gamma-HCH on the testicular metabolism of H-3-17P was examined by thin layer and high performance liquid chroma tography. Endogenous production of T was stimulated by 1 mg/L gamma-HC H but inhibited at higher doses, while its glucuronide was higher in a ll incubations containing gamma-HCH compared with controls. 17P and KT production was lower at all concentrations of gamma-HCH compared with controls, but the low endogenous 17,20 beta P production was unaffect ed. gamma-HCH had a much lower impact on the metabolism of exogenous 1 7P than on endogenous precursors. The major metabolite of 17P in the t estis, 17,20 beta P, showed a significant increase in yield in respons e to gamma-HCH together with a decrease in production of its glucuroni de. There was also a significant increase in yield of testosterone at some concentrations, but none of the other metabolites were affected b y gamma-HCH exposure. The results show that the balance of steroid pro duction by testes of spermiating roach is significantly perturbed by g amma-HCH and suggests that the pesticide affects predominantly the sta ges of steroidogenesis leading to 17-hydroxyprogesterone production.