The effects of probucol on liver and intestinal apolipoprotein, LDL-receptor and hepatic lipase gene expression, as well as plasma lipid and apolipoprotein levels and liver lipase activity were evaluated in male rats. Administration of probucol decreased plasma triacylglycerols, without affecting plasma cholesterol. Plasma apo E and apo B concentrations increased after probucol. Since liver and intestinal apo B and apo E mRNA levels remained unchanged, this increase could be attributed to a delayed clearance by the LDL-receptor, whose mRNA levels dropped by 50% in the liver. For the HDL-apolipoproteins, only liver apo A-IV mRNA levels decreased after probucol, which was reflected by a fall of plasma apo A-IV. Neither hepatic lipase activity nor mRNA levels were significantly influenced by probucol.