Effects of cholesterol feeding on the distribution, metabolism, and accumulation of pentachlorobenzene in rats.

To investigate the influence of cholesterol content in tissue on the distribution, metabolism, and accumulation of pentachlorobenzene (PECB), rats were fed on a cholesterol-enriched (CHE) diet or a basal diet for 4 weeks. At two weeks, a single dose or a 6-day dosage of PECB was orally administered. The serum cholesterol concentration in the CHE diet group was 2.1-2.9 times higher than that in the basal diet group, while the serum triglyceride concentration decreased. The serum lipid levels were similar to the levels at two weeks. The blood PECB concentration was not different between the two groups. Increases in the contents of PECB and lipid in tissue due to the CHE diet feeding were observed only in liver (PECB, 2.6-3.0 times; triglyceride, 2-3 times; cholesterol, 10-15 times). Content of pentachlorophenol, a main metabolite of PECB, and the level of drug-metabolizing enzymes in liver of the CHE diet group tended to be higher than those of the basal diet group. These results suggested that the increase in PECB accumulation in the liver of the CHE diet group was not due to the decrease of PECB metabolism but due to the increase in the content of cholesterol and triglyceride.