[Mechanism of the cardiotoxic action of No-Spa].
Tests set up in vivo on rats and with an isolated spontaneously contracting atrium of the cat brought evidence that nospanum produces an adverse chronotropic action, caused by a direct effect on the cardiac pacemaker. In the rat's myocardium the drug raised the pyruvate level, increased the lactate-dehydrogenase activity and depressed that of glucose-6-phosphate-dehydrogenase. As established by differential spectrophotometry the reduced forms of pyridine-nucleotides (NAD'N, NADP'N) tend to change the nospanum spectrum. An addition of potassium chloride to an isolated atrium at the peak of the adverse chronotropic action of nospanum or an introduction of nospanum together with NAD'N abolished the cardiotropic effect of the drug. The mechanism of the cardiotoxic action of nospanum is discussed.
[Mechanism of the cardiotoxic action of No-Spa]. Tests set up in vivo on rats and with an isolated spontaneously contracting atrium of the cat brought evidence that nospanum produces an adverse chronotropic action, caused by a direct effect on the cardiac pacemaker. In the rat's myocardium the drug raised the pyruvate level, increased the lactate-dehydrogenase activity and depressed that of glucose-6-phosphate-dehydrogenase. As established by differential spectrophotometry the reduced forms of pyridine-nucleotides (NAD'N, NADP'N) tend to change the nospanum spectrum. An addition of potassium chloride to an isolated atrium at the peak of the adverse chronotropic action of nospanum or an introduction of nospanum together with NAD'N abolished the cardiotropic effect of the drug. The mechanism of the cardiotoxic action of nospanum is discussed.