title: Histochemical, ultrastructural and cytochemical study of reperfusion effect on ischemic myocardial injury.
abstract: We assessed the histochemical, ultrastructural and cytochemical effects of reperfusion on ischemic myocardial cells during the early and late reperfusion phases in two groups of dogs. Group A were 8 dogs undergoing 1 hour occlusion of LAD, and Group B were 14 dogs undergoing 1 hour occlusion of LAD followed by 2 hour reperfusion period. The results of the histochemical study (PAS stain) demonstrated that in Group A, a patchy distribution of glycogen occurred primarily in the subepicardial region. Three-dimensional analysis of this distribution revealed peninsulas of glycogen running parallel with a vessel. The cells in Group B, mainly subepicardium, showed a moderate glycogen content which was more extensive than those in Group A. The ultrastructural changes were assessed after a 60-minute ischemia and subsequent recovery (after 5 minutes and 120 minutes of reflow) using transmural biopsy specimens. Each myocardial cell was graded from 0-4 according to the degree of ischemic injury and recovery. The degree of ischemic damage varied in intensity from slight to severe, in both the subepicardium and the subendocardium. Ca++-ATPase activity was examined cytochemically in myocardial cells of Group B. After 60-minute occlusion, the moderately ischemic cells (especially in the subepicardium) that were without amorphous dense bodies or marked sarcolemmal lifting-off made significantly greater ultrastructural recovery (p less than 0.05) with restoration of Ca++-ATPase activity on sarcoplasmic reticulum and mitochondria after 120 minutes of reflow. This occurred even though after 5 minutes of reflow the cell showed temporary deterioration such as contraction bands, vacuoles and severe destruction of some mitochondria.
authors.forename: T
authors.initials: T
authors.lastname: Fukuhara
mesh_terms: D000818:Animals; D000252:Calcium-Transporting ATPases / Q000378:metabolism; D003327:Coronary Disease / Q000378:metabolism / Q000473:pathology*; D003331:Coronary Vessels / Q000601:surgery; D003599:Cytoskeleton / Q000378:metabolism; D004285:Dogs; D005260:Female; D006003:Glycogen / Q000378:metabolism; D008026:Ligation; D008297:Male; D008854:Microscopy, Electron; D008929:Mitochondria, Heart / Q000378:metabolism; D009206:Myocardium / Q000378:metabolism / Q000648:ultrastructure*; D010477:Perfusion; D012519:Sarcoplasmic Reticulum / Q000378:metabolism
chemical_list: D006003:Glycogen; D000252:Calcium-Transporting ATPases