[Myocardial phosphorylase activity in rats with spontaneous and metacorticoid hypertension treated with isoprenaline and untreated].

The authors examined the activity of the enzyme phosphorilase in the myocardium of rats with spontaneous hypertension of the Okamoto Aoki type and of Wistar rats with experimental metacorticoid hypertension. They found higher basal activity of phosphorilase "a" in the both groups of hypertonic rats. After treatment of rats with isoprenaline in a dose of I mg/kg, administered intraperitonealy, the phosphorilase "a" in the myocardium of hypertensive animals was activated to a degree equal to that of the normotensive rats. This correlated also with the maximal isoprenaline chronotropic response in the both groups of hypertensive rats. The authors discussed the possible causes and mechanisms for the observed changes and effects.