The influence of nifedipine and verapamil on the ischaemia-induced changes in canine sarcolemmal membranes.

Abstract

Ischaemic injury was produced in the dog heart by occluding the left anterior descending coronary artery just below the second diagonal branch for the duration of 3 h. Nifedipine 5.0 mg/kg and Verapamil 5.0 mg/kg were injected intravenously 10 min before the occlusion. Sarcolemmal membrane vesicles were prepared from an ischaemic and non-ischaemic hearts. Without treatment with Nifedipine or Verapamil the total amount of sarcolemmal phospholipid obtained from ischaemic hearts, as well as the amounts of phosphatidylcholine and phosphatidylethanolamine were significantly decreased as compared with those from non-ischaemic hearts. Calcium channel blocker pretreatment abolished the decrease in the total amount of sarcolemmal phospholipids, as well as phosphatidylcholine and phosphatidylethanolamine content induced by ischaemia. Thus, our work indicates that Nifedipine and Verapamil, suppressed the ischaemia-induced increase in phospholipid breakdown of cardiac sarcolemma.