In vitro cyclic AMP induced phosphorylation of phospholamban: an early marker of long-term recovery of function following reperfusion of ischaemic myocardium?

• Published in: Cardiovascular research Vol. 22; no. 10; pp. 714 - 718
• Main Authors: GIESSEN, WILLEM J van der, VERDOUW, PIETER D, CATE, FOLKERT J ten, ESSED, CATHERINA E, RIJSTERBORGH, HANS, LAMERS, JOS M J
• Format: Journal Article
• Language: English
• Published: Oxford Oxford University Press 01.10.1988
• Subjects: Animals; Biological and medical sciences; Blood Pressure; Calcium-Binding Proteins - metabolism; Cardiology. Vascular system; Coronary Disease - pathology; Coronary Disease - physiopathology; Coronary heart disease; cyclic AMP; Cyclic AMP - pharmacology; echocardiography; Heart; Heart - physiopathology; Heart Rate; Medical sciences; membrane biochemistry; Myocardial Reperfusion; Myocardium - ultrastructure; Phosphorylation; pigs; protein phosphorylation; regional myocardial function; reperfusion; Swine; two-dimensional; ultrastructure; Sarcolemma; Phosphorylation; Acute; Cyclic AMP; Biological marker; Cardiovascular disease; Phospholamban; Coronary heart disease; In vitro; Myocyte; Pig; Vertebrata; Experimental disease; Mammalia; Ischemia; Biopsy; Myocardium; Artiodactyla; Ungulata
• ISSN: 0008-6363; 1755-3245
• DOI: 10.1093/cvr/22.10.714

Changes in myocardial membrane biochemistry and ultrastructure, determined shortly (2 h) after reperfusion of ischaemic myocardium, were compared with the long term (4 wk) recovery of regional myocardial function. Anaesthetised pigs were subjected to 30 min (n= 14, group I) or 60 min (n=14, group II) of left circumflex coronary artery occlusion. Seven animals of each group were studied 2 h and the others 4 weeks after flow was reinstated. After 2 h of reperfusion, regional myocardial function was absent in both groups. At 4 weeks regional function had returned to normal in group I, but was still significantly depressed in group II. Biochemical studies after 2 h of reperfusion showed that a functional index of the cardiac membrane, the in vitro cyclic AMP dependent 32P incorporation into phospholamban, was 71 (SEM 9)% compared to non-ischaemic myocardium in group I and 31 (6)% in group II (p<0.05). After 4 weeks this index had completely recovered in group I, 114 (13)%, but a significant decrease to 79 (2)% could still be observed in group II (p<0.05). After 2 h of reperfusion as well as after 4 weeks of recovery the myocytes in group II were more severely damaged than in group I. This study suggests that determination of in vitrophosphorylation of phospholamban shortly after reperfusion of ischaemic myocardium may be of value in the prediction of long term recovery of regional myocardial function.