THE INHIBITORY EFFECT OF BEVANTOLOL ON THE ACCUMULATION OF NON-ESTERIFIED FATTY ACIDS DURING ISCHAEMIA IN THE DOG HEART IN SITU

1. The left anterior descending coronary artery (LAD) was completely ligated for 90 min (i.e. myocardial ischaemia was produced) in the dog anaesthetized with pentobarbital. 2. Bevantolol, a beta 1-adrenoceptor antagonist, was injected (1 mg/kg, intravenously) 5 min before LAD occlusion. The bevantolol injection decreased heart rate without affecting blood pressure. 3. The myocardial samples were taken from the LAD area immediately after the end of LAD occlusion, and were subjected to analysis of the myocardial levels of non-esterified fatty acids (NEFA). 4. In dogs in which saline was injected, ischaemia produced accumulation of NEFA, especially arachidonic and palmitoleic acids, in the myocardium. 5. In dogs in which bevantolol was injected, the accumulation of NEFA induced by ischaemia was almost completely inhibited. 6. It is concluded that bevantolol inhibits ischaemia-induced accumulation of NEFA in the myocardium, and that stimulation of the beta 1-adrenoceptors is probably responsible for NEFA accumulation induced by ischaemia.