ULTRASTRUCTURE OF CULTURED ADULT MYOCARDIAL-CELLS DURING ANOXIA AND REOXYGENATION

  • 1 January 1984
    • journal article
    • research article
    • Vol. 115  (3) , 349-361
Abstract
Cultured heart cells from adult rats were exposed to anoxia in a substrate-free Tyrode''s solution at constant pH. In this stystem the metabolic and the morphologic pattern can be investigated simultaneously. Anoxic changes develop gradually above 2 .mu.mol ATP/gww. Morphometry reveals that the morphologic changes are closely related to the energetic state: creatine phosphate (CP) decay is accompanied by the loss of small mitochondrial matrix granules (r = 0.97). The fall of ATP is coincident with sarcomere shortening (r = 0.95) and, below 4 .mu.mol/gww, with mitochondrial swelling (r = -0.88). The number of lipid droplets correlates with the ATP level during anoxia and reoxygenation (r = -0.92). The early energetic depletion is accompanied by a moderate release of cytosolic enzymes and morphologic changes: the appearance of sarcolemmal microblebs and an increase in subsarcolemmal vesicles. Below an average ATP level of 2 .mu.mol/gww an increasing number of individual cells fail to recover when reoxygenated. Failure is accompanied neither by massive enzyme relase nor by ultrastructural damage regarded as typical for the oxygen paradox.