The effects of bilateral adrenalectomy on the fine structure of the rat myocardium

The subcellular effects of bilateral adrenalectomy on the rat myocardium were examined on 50 male rats. The animals, divided into groups of ten, were killed 3, 17, 18, 19 and 21 after adrenalectomy. The early changes consisted of moderate intracellular edema of many cardiac muscle cells and disarrangement of their myofibrils. The late changes consisted of prominent intracellular edema of many cardiac muscle cells, destruction of numerous myofibrils, dilatation of the sarcoplasmic reticulum and accumulation of numerous irregular mitochondria in subsarcolemma areas of the sarcoplasm. The lipofuscin granules seemed to be increased in number. Many endothelial cells were edematous and platelet aggregations filled the lumen of some small vessels.