Sex Differences in Hepatic Lipids of Toxaphene-Exposed Juvenile Yellowtail Flounder (Pleuronectes ferrugineus Storer)

Histochemical and biochemical effects of Toxaphene on liver were investigated in laboratory-bred female and male juvenile yellowtail flounder (Pleuronectes ferrugineus). Fish were fed uncontaminated food, or food contaminated with hexane (the solvent for Toxaphene) or with one of two concentrations of Toxaphene (0.02 or 0.2 μg/g fish/day) for 2 weeks. Males were more advanced in sexual maturity than females, although all were from the same year-class (0+). Liver tissue examined histochemically (Sudan black B, oil red O) revealed that Toxaphene affected storage of total and neutral lipids according to sex and dose. The sexes differed in the amount of total and neutral lipids. Neutral lipid droplets were considerably larger in the liver of females. Lipids were extracted and analyzed using the latroscan TLC/FID system. Triacylglycerols comprised the majority of lipids. Animals exposed to the lowest concentration of Toxaphene stored low amounts of total and neutral lipids and high amounts of polar lipids, while animals exposed to a 10 times higher concentration showed the reverse. Sterols were highest in animals exposed to the highest dose. Thus Toxaphene can alter the lipid composition in the liver of yellowtail flounder, which may have consequences for physiological processes involving the liver, such as lipid metabolism and reproduction.