Effects of propranolol on myocardial ultrastructure, mitochondrial function and high energy phosphates of isolated working rat hearts with coronary artery ligation

Abstract

The effects of coronary artery ligation on myocardial ultrastructure, high energy phosphate contents and mitochondrial oxidative phosphorylation were studied in the isolated, perfused working rat heart model. The changes in ultrastructure, mitochondrial function and high energy phosphate contents of the ischaemic tissue were characteristic of severe ischaemic damage, showing a good correlation between ultrastructural and functional changes. To determine whether these changes could be prevented, reduced or delayed by beta-blockade, propranolol (3 × 10 −7 and 3 × 10 −6 m) was added to the perfusate. In our model propranolol did not exert a protective effect on the ultrastructure, tissue high energy phosphate contents and mitochondrial oxidative function except for a significant increase in Q O 2 (State 3) with propranolol at a concentration of 3 × 10 −7 m.