Effect of guanethidine on contractile activity and ultrastructure of the myocardium in rabbits (Russian)

The influence of therapeutic doses of guanethidine (1 mg/kg of body weight) and double this dose, on the contractile activity and ultrastructure of the myocardium and on catecholamine content in cardiac muscle and adrenal glands was studied using rabbits. A 0.1% solution of the drug was administered subcutaneously for 14 days. It was established that a 2 wk period of guanethidine administration resulted in weakening of the contractile activity of the left ventricle, and decrease of epiniphrine and norepinephrine content in the myocardium. Electron microscopy of the myocardium showed changes in ultrastructure of muscle cells, intracellular deposits of glycogen, increase of lipid content and some mitochondrial destruction. The data obtained reveal disorders of energy metabolism in muscle cells due to guanethidine.