Long-term heparin infusion and plasma lipoprotein lipase activity

The effect of a prolonged intravenous infusion of heparin on plasma lipolytic activity has been studied in 5 patients following recent myocardial infarction. The level of lipoprotein lipase in the plasma fell over the first 3-7 days, and then rose to a level higher than that present on the first day of the heparin infusion. This secondary peak was followed by a further fall in plasma activity.

The fluctuations in plasma lipoprotein lipase activity may have been due to changes in the sensitivity of the patients to heparin. Whether this was the result of acute myocardial infarction is not clear, as no control studies have been performed. The initial low levels of plasma enzyme may have been due to suppression of enzyme synthesis by high levels of plasma catecholamines and free fatty acids following the infarction.