Experiments on rats showed that theophylline, theobromine, and caffeine in a dose equimolar to 50 mg/kg of theophylline base, increase the catecholamine concentration in the rat myocardium 1 h after intraperitoneal injection. These compounds, except caffeine, had a similar effect in a dose of 125 mg/kg. Theophylline reduced the degree of lowering of the catecholamine level in the myocardium after administration of tyramine and strophanthin. Elevation of the catecholamine level after administration of caffeine was accompanied by an increase in the ATP and ADP content and a decrease in the AMP content, as well as by the formation of inosine monophosphate, adenosine, and inosine.
Key Words myocardium - methylxanthines - catecholamines - adenosine phosphates
Central Research Laboratory and Department of Pharmacology, Kiev Medical Institute. (Presented by Academician of the Academy of Medical Sciences of the USSR A. I. Cherkes.) Translated from Byulleten'' Éksperimental''noi Biologii i Meditsiny, Vol. 78, No. 10, pp. 61–64, October, 1974.