IN-VIVO INCORPORATION OF [1-C-14]ACETIC ACID INTO LIVER LIPIDS OF GOLDFISH, CARASSIUS-AURATUS, DURING GAMMA-HEXACHLOROCYCLOHEXANE EXPOSURE

Male and female specimens of Carassius auratus were exposed to safe (SC; 0.01 mg/L) and sublethal concentrations (SL; 0.1 mg/L) of an organochloride pesticide-gamma-hexachlorocyclohexane (gamma-HCH) for 4 weeks. On the last day of exposure, 18 h before sacrifice, when they were in the reproductively active prespawning phase of their annual reproductive cycle, fish were treated intramuscularly with [1-C-14]acetic acid (74 kBq per fish). After 4 weeks of exposure, the effect of gamma-HCH on the hepatic incorporation of [1-C-14]acetic acid into total lipids (TL) and its various fractions (free fatty acids (FFA), monoglycerides (MG), diglycerides (DG), triglycerides (TG), free cholesterol (CF), esterified cholesterol (CE) and total phospholipids (TP) and its fractions (phosphatidylcholine (PC), phosphatidylserine (PS), phosphatidylinositol (PI) and phosphatidylethanolamine (PE)) was monitored. In males, hepatic incorporation of [1-C-14]acetic acid into FFA, MG, CF, CE, PS and PI increased significantly, while incorporation into TG, TP, PC and PE was significantly reduced after gamma-HCH exposure. In females, [1-C-14]acetic acid incorporation was significantly higher for TL, FFA, TP, CE, PC, PS, PI and PE, and lower for MG, DG, TG and CF after gamma-HCH exposure. The rapid incorporation of [1-C-14]acetic acid into TL, FFA and CE, but decreased uptake into TG, indicates that gamma-HCH did not impair the incorporation into FFA but promoted esterification of CF (sex steroid precursor) into CE as well as further inhibiting the esterification of FFA into MG, DG and TG. It was concluded that gamma-HCH exposure affected the hepatic incorporation of [1-C-14]acetic acid into nonpolar and polar lipids depending upon sex, therapy affecting synthesis and release of lipids required for ovarian recrudescence in this species.