Glycogen content of cells adjacent to infarcts in nontreated animals and animals treated with insulin was studied. Distribution of glycogen in ischemic and anoxic myocardial cells was likewise investigated. Experiments were performed on swine, calves and monkeys. Myocardial lesions were produced in vivo by gradual occlusion, by ligation of the coronary arteries and by direct injection of plastic microspheres. Anoxia, without reduction of vascular flow, was produced by perfusion in vitro with bloodless fluids. Glycogen content was determined histochemically by the use of PAS technique and by metachromatic staining of sodium bisulfide addition derivatives. Sections were likewise examined with an electron microscope. Excessive accumulation of glycogen was found in cells adjacent to infarcts, and myocardial cells rendered ischemic by narrowing of arteries and microsphere injection. Accumulation of glycogen was not observed in cells around the infarcts in animals given insulin, nor in perfused hearts. Glycogen granules in ischemic cells were noted in electron microscope preparations, as were the loss of organized myofibrils and the appearance of disorganized network of myofilaments. These observations suggest that abnormal accumulation of glycogen takes place in the myocardial cells which undergo changes adaptive to ischemia. Administration of insulin may aid the process of adaptation by eliminating glycogen which these cells cannot metabolize.
|State||Published - Dec 1 1973|
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