title: Loss of myocardial CK-MB into the circulation following 3.5 hours of swimming in a rat model.
abstract: The purpose of this study was to document alterations of creatine kinase-B (CK-B) in the left and right ventricles of rats and CK-MB release into the circulation following a single bout of stressful prolonged intense exercise. Male Sprague-Dawley rats, with 8% bodyweight attached to each tail, were forced to swim 3.5 hours and were then sacrificed immediately (0 h PS), 3 hours (3 h PS), 24 hours (24 h PS), and 48 hours (48 h PS) post swimming, respectively. Sedentary (control) rats were sacrificed at rest. Serum CK-MB mass increased 2.1 times (8.9 microg/L; p < 0.01 vs. controls of 4.3 microg/L) and 1.4 times (6.0 microg/L; P < 0.01 vs. controls) at 0 h PS, and 3 h PS, respectively, and returned to baseline at 24 h PS. Western blot analysis indicated that CK-B of the right ventricle decreased 14% (p < 0.05), 20% (p < 0.01), and 12% (p < 0.05) at 3h PS, 24h PS and 48h PS, respectively. The CK-B of the left ventricles decreased 34% (p < 0.05) at 0 h PS, returned to baseline at 3 h PS, and was increased 39% (P < 0.01) at 48 h PS. Our findings demonstrate that a single bout of stressful, prolonged, intense exercise resulted in CK-B subunit loss from the myocardium, resulting in increased serum CK-MB concentrations, an indication of myocardial injury.
authors.affiliation: Division of Kinesiology, School of Kinesiology and Leisure Studies, University of Minnesota, USA.
authors.forename: Y J
authors.initials: YJ
authors.lastname: Chen
authors.forename: R C
authors.initials: RC
authors.lastname: Serfass
authors.forename: F S
authors.initials: FS
authors.lastname: Apple
mesh_terms: D000818:Animals; D003402:Creatine Kinase / Q000097:blood*; D052276:Creatine Kinase, BB Form; D052279:Creatine Kinase, MB Form; D006352:Heart Ventricles / Q000737:chemistry* / Q000473:pathology; D007527:Isoenzymes / Q000097:blood*; D008297:Male; D009206:Myocardium / Q000473:pathology; D010805:Physical Conditioning, Animal / Q000502:physiology*; D051381:Rats; D017207:Rats, Sprague-Dawley; D013550:Swimming / Q000502:physiology*
chemical_list: D007527:Isoenzymes; D003402:Creatine Kinase; D052276:Creatine Kinase, BB Form; D052279:Creatine Kinase, MB Form