[Influence of sodium selenite on cardiac myodynamic effects (author's transl)].
Left ventricular pressure (LVSP), the first derivative of left ventricular pressure (dP/dt), heart rate (HR), common peak isovolumeric pressure (CPIP), dP/d/CPIP (Vce at CPIP), tesion time index of ventricular ejection(TTI), and t-dP/dtmax were measured in 16 anesthetized open-chest dogs. The tension of left ventricular wall was measured simultaneously by a strain gauge arch sutured on the left ventricle. Iv Na2SeO3 1 mg/kg in 9 dogs markedly decreased BP, LVSP, TTI, dP/dt/CPIP and LYCF, and prolonged t-dP/dtmax. Na2SeO3 3.3 and 6.5 μg/ml obviously depressed cardiac contractile force of isolated rabbit hearts, but there was no significant change of coronary blood flow. Na2SeO3 12.5 μg/ml showed an inhibitory effect on isolated rabbit atria. Na2SeO3 38, 187 and 375 μg/ml mark-edly produced negative inotropic effects on isolated toad hearts. The tolerance of isolated toad hearts to Na2SeO3 was about 10 times larger than that of isolated rabbit hearts. Na2SeO3 and verapamil antagonized the positive inotropic action of Ca2+ but that of adrenaline. The negative inotopic action of Na2SeO3 could be responsible for the effect in antagonism to Ca2+.