On the mechanism of action of cobalt ion on the isolated heart

Abstract

The effects of cobalt ion on the isolated heart of the guinea-pig were studied. The addition of cobalt to the incubation medium ceases the contractions of the isolated heart. The effect of cobalt ion could be prevented by the addition to the incubation medium of calcium ion in equimolar concentrations. Cobalt ion prevented the effects of 1-epinephrine and 1-norepinephrine and these effects of the cation, were antagonized by the presence of calcium ion in amounts not sufficient to antagonize completely the effects of cobalt ion. The mechanism of action of cobalt ions on the isolated heart was discussed. It was proposed that cobalt ion prevents the utilization of calcium ion in the physiological process supporting the mechanical activity of the isolated heart.