title: The effects of post-mortem changes and calcium depletion on the ultrastructure of myocardial cells in a teleost.
abstract: The effects of post-mortem changes and calcium depletion on the ultrastructure of myocardial cells in a teleost, Gadus virens L., are described. When incubated at 4 degrees C in cacodylate buffer/Ringer's solution for 8 h some few myocardial cells appear swollen and their mitochondria contain several small (50-250 nm) flocculent densities. In tissue incubated for at least 80 h the mitochondria in all myocardial cells contain a number of such densities. Also, the size of these structures seems to increase with incubation time. Further, after being incubated for at least 150 h the myofibrils appear often twisted and broken, and the electron density of the Z and I bands gradually declines. At prolonged incubation times (about 1,000-1,300 h) the actin filaments and Z band material seem gradually to dissolve, whereas the myosin filaments still make up a distinct A band. Intercalated discs in tissue incubated in calcium-free medium for 4-28 h appear to display a nearly normal structure. The results of the present study are compared with those previously reported for mammals. The observed differences in decomposition rates within teleostean myocardial tissue are discussed.
mesh_terms: D000818:Animals; D002118:Calcium / Q000378:metabolism; D003599:Cytoskeleton / Q000648:ultrastructure; D005399:Fishes / Q000033:anatomy & histology*; D006352:Heart Ventricles; D008854:Microscopy, Electron; D008929:Mitochondria, Heart / Q000648:ultrastructure; D009206:Myocardium / Q000648:ultrastructure*; D009210:Myofibrils / Q000648:ultrastructure; D011180:Postmortem Changes
chemical_list: D002118:Calcium