Effects of trichloroethylene, 1,1,1-trichloroethane and carbon tetrachloride on plasma lipoproteins of rats.

Abstract

Effects of single intraperitoneal administration of trichloroethylene, 1,1,1-trichloroethane, and carbon tetrachloride (positive control) on the plasma contents of lipoproteins were investigated in rats. Plasma was fractionated to VLDL, LDL, and HDL by sequential ultracentrifugation. On the administration of carbon tetrachloride at 30 to 1000 mg/kg, VLDL and HDL were reduced dose-dependently, but the reduction in LDL was not dose-dependent. With trichloroethylene at 30 to 300 mg/kg, the lipid contents of VLDL and LDL fractions were decreased. At 1000 mg/kg, VLDL and LDL was increased by the trichloroethylene. The HDL was decreased with increasing doses of trichloroethylene at 30 to 1000 mg/kg. With 1,1,1-trichloroethane at 100 to 300 mg/kg, VLDL and LDL were increased. The HDL levels rose at 100 mg/kg but fell at 1000 mg/kg. Thus trichloroethylene impairs VLDL formation at low doses. 1,1,1-Trichloroethane stimulates the VLDL synthesis at low doses and inhibits it at high doses. The decreases in HDL at high doses of trichloroethylene and 1,1,1-trichloroethane resulted from the inhibition of HDL synthesis. Liver-to-body weight ratios were raised with increasing doses of carbon tetrachloride, trichloroethylene, and 1,1,1-trichloroethane. Plasma GOT and GPT activities rose at much higher doses of solvents than dose levels which produce the changes in lipoproteins and the increases in liver weights. The liver enlargement appeared to be a sensitive marker of hepatotoxicity related to the changes in lipoproteins, the profile of which was different in three solvents.