Effects of cigarette smoking and dietary lipids on rat lipoprotein metabolism

The effects of cigarette smoke inhalation on rat lipoprotein metabolism have been examined. Rats were subjected to cigarette smoke exposure over a 3-week period (two 1-h sessions/day) using a Bat-Mason inhalation machine. Rats exposed to cigarette smoke showed a decrease in total serum triglyceride and an increase in very low density lipoprotein cholesterol (VLDL-C). Administration of cigarette smoke to rats fed a saturated fat and cholesterol enriched diet also led to an increase in VLDL-C and a decrease in total serum triglycerides compared to controls. In addition, cigarette smoke exposure to animals fed the lipid enriched diet caused a decrease in high density lipoprotein cholesterol (HDL-C). Pair-feeding experiments indicated that the increase in VLDL-C and the decrease in HDL-C could not be solely attributed to the reduction in food intake and the small decrease in growth rate observed following cigarette smoke exposure. The changes observed in VLDL-C and HDL-C are at least qualitatively similar to the changes seen in human smokers compared to non-smokers.