[Changes in the activity of glycogen phosphorylase in the rat myocardium after immobilization stress]

Immobilization stress with duration of 6, 12 and 24 hours was induced in rats of Wistar strain. The rats of the control group were without food and water for the same periods of time. The active form a of glycogen phosphorylase, total enzymic activity a-b and the percentage of the active form of the total enzymic activity in the myocardium of the left ventricle, right ventricle and intraventricular septum were determined. There were no statistically significant differences in the activity of phosphorylase a and in the total enzymic activity between the control and experimental animals on the sixth hour since the onset of the study. The activity of both forms of the enzyme in the right ventricle and septum was higher in comparison with that of the control animals after 12 hours of immobilization. The enzymic activity was reduced in comparison with that of the control animals after 24 hours of immobilization. It could be assumed that metabolic adaptive mechanism of the cardiac muscle improve conditions for formation of energy from carbohydrate sources.