EFFECT OF ETHANOL INTOXICATION AND CATECHOLAMINES ON CARDIAC LIPOPROTEIN LIPASE ACTIVITY IN RATS

¹ Department of Pharmacology, State University of New York, Upstate Medical Center, Syracuse, New York

The effect of acute ethanol intoxication on the lipoprotein lipase (LPL) activity of rat tissues was investigated. Ethanol intoxication, as well as the i.m. injection of epinephrine or norepinephrine, or subjection to ether anesthesia induced significant increases in cardiac LPL activities as determined in homogenates or slices of heart ventricle. The effects were readily seen after a period of 3 to 4 hr but were not manifested within 1 hr after the i.p. administration of ethanol or after 10 min of i.v. infusion with epinephrine. No effect on LPL activity was observed when ethanol or epinephrine was added in vitro. Elevation of the lipase activity was seen after ethanol intoxication if serum-activated coconut oil emulsion was used as substrate in the assay. The lipase activity affected by ethanol was inhibited in vitro by protamine sulfate, 1 M NaCl and diisopropyl fluorophosphate and enhanced by heparin. The effect of ethanol did not occur in reserpine-treated adrenalectomized rats or in rats treated with puromycin. A beta-adrenergic blocking agent inhibited the effects of both ethanol and epinephrine, while several alpha-adrenergic blocking agents enhanced LPL activity and did not prevent the effect of ethanol.