Changes in creatine kinase M localization in acute ischemic myocardial cells. Immunoelectron microscopic studies.
To clarify the changes in creatine kinase M localization along with the progress of myocardial ischemia, immunoelectron microscopic studies were performed using rabbit anti-canine creatine kinase M Fab'-horseradish peroxidase conjugate in 21 dogs. Myocardial ischemia was induced by occlusion of the left anterior descending coronary artery for 15 (n = 5), 30 (n = 5), 60 (n = 5), or 180 (n = 4) minutes. Two dogs were used as normal controls. As we have already demonstrated, most creatine kinase M in normal myocardial cells was localized over the entire A band in association with the thick filament, suggesting that creatine kinase in this region (A-band creatine kinase) was the enzyme coupled with myosin ATPase. After 15 minutes of ischemia, creatine kinase M showed only minimal changes in its location, indicating that A-band creatine kinase still has the ability to couple with myosin ATPase (reversible injury). However, after 30 minutes of ischemia, A-band creatine kinase diffused markedly to the I band (transitional phase), and after 60 minutes of ischemia, it leaked out to extracellular spaces (irreversible injury). After 180 minutes of ischemia, most A-band creatine kinase disappeared from the myocardial cells (coagulation necrosis). These features of creatine kinase M localization seemed to reflect each stage of ischemic cell injury. We conclude that myocardial ischemia results in a dissociation of creatine kinase molecules from the thick filament, which leads the energy transport system to destruction.
Otsu
N
N
Department of Clinical Laboratory, Yamagata University School of Medicine, Japan.
Yamaguchi
I
I
Komatsu
E
E
Miyazawa
K
K
D000208:Acute Disease; D000818:Animals; D003402:Creatine Kinase / Q000032:analysis*; D004285:Dogs; D007527:Isoenzymes; D016253:Microscopy, Immunoelectron; D017202:Myocardial Ischemia / Q000201:enzymology* / Q000473:pathology; D009206:Myocardium / Q000201:enzymology* / Q000648:ultrastructure; D009218:Myosins / Q000032:analysis
D007527:Isoenzymes; D003402:Creatine Kinase; D009218:Myosins