Metabolic disorders associated with hyperlipemia: activity of an extremely potent hypolipemic agent (LR 19731)

LR 19731 [4-p-chlorophenyl-5-beta-(N'-phenyl)piperazinoethyl-1,3-dioxolin-2-one] lowers the plasma cholesterol and triglyceride levels of rats in several experimental conditions after single or repeated treatments, while it is scarcely active on liver lipids. The compound is especially effective in reducing plasma cholesterol in a dose-related manner both in normolipemic and hyperlipemic rats. The minimal effective dose (after five oral treatments in 4 days to normolipemic rats) is as low as 3 mg/kg, the ED50 is 11.3 mg/kg, while the maximal effective dose capable of completely suppressing plasma cholesterol is 100 mg/kg. Surgical removal of the thyroid gland does not influence its activity. At its ED50 the compound does not cause hepatomegaly, accumulation of desmosterol in plasma and liver. Under the same experimental conditions clofibrate presents a poor dose-response correlation on plasma lipids and generally appears at least 10 times less active than LR 19731 on cholesterol but more effective on liver weight. The experiments of general pharmacology indicate that LR 19731 does not effect central and peripheral nervous functions, does not influence the cardiovascular system or cause skeletal muscle relaxation, hypothermia, analgesia, and does not possess anti-inflammatory properties up to a dose of about 100 mg/kg.