The effect of acute and chronic administration of nicotine on lipoprotein lipase activity

Nicotine was injected intraperitoneally to rats and 2 h later lipoprotein lipase was determined in isolated perfused hearts. There was a significant increase in heparin releasable lipoprotein lipase activity which represents the functional pool without increase in total enzyme activity. When 1 microliter/h of a solution of nicotine (120 mg/ml) was delivered for 3 days from subcutaneously implanted miniosmotic pumps, total lipoprotein lipase activity in the heart increased 1.5-3.0 fold. Endogenous lipoprotein lipase activity in plasma doubled and there was a significant fall in plasma triglyceride levels. The effect of nicotine on heart lipoprotein lipase activity was evident also after 6 days of continuous delivery and was accompanied by a fall in adipose tissue lipoprotein lipase activity. No effect was seen when the dose of nicotine was halved. A positive correlation was seen between plasma nicotine levels and heart lipoprotein lipase activity, while adipose tissue lipoprotein lipase correlated negatively with plasma nicotine levels. Chronic administration of nicotine was accompanied by either weight loss or diminished weight gain. It is concluded that in the rat the acute effect of nicotine on the shift of lipoprotein lipase to the functional pool could be related to enhanced beta-adrenergic stimulation. The chronic effect of nicotine could have been mediated by the loss in body weight, due to reduced caloric intake.