Propranolol inhibits accumulation of non-esterified fatty acids in the ischemic dog heart.

The effects of propranolol and d-propranolol on the accumulation of non-esterified fatty acids (NEFA) induced by complete occlusion of the left anterior descending coronary artery (LAD) for 90 min, were investigated in dogs anesthetized with pentobarbital. The myocardial levels of eight NEFA (lauric, myristic, palmitic, palmitoleic, stearic, oleic, linoleic and arachidonic acids) were determined after fluorescent labelling of the NEFA with 9-anthryldiazomethane. LAD occlusion increased the myocardial levels of NEFA, especially those of arachidonic and palmitoleic acids; arachidonic acid increased by 3.5 times and palmitoleic acid by 2.9 times. Pretreatment with propranolol (1 mg/kg) inhibited almost completely the accumulation of NEFA induced by occlusion of the LAD, whereas pretreatment with d-propranolol (1 mg/kg) did not inhibit the accumulation of NEFA, although it tended to inhibit the accumulation of palmitoleic, stearic and arachidonic acids. These results suggest that the inhibitory action of propranolol on the accumulation of NEFA in the myocardium during ischemia is mainly due to its antagonistic effect at beta-adrenoceptors and probably partly due to its effect as a local anesthetic.