[Impairing effect of ouabain on heart muscle slices of guinea pigs].

In heart slices of guinea pig, ouabain (10(-5) M) causes not only an inhibition of the Na+,-K+-ATPase but also damage of the cell membrane. This leads to an efflux and a degradation of the cellular NADH and NAD. By addition of these constituents to the incubation medium an increasing inhibition of the tissue respiration, caused by ouabain, is prevented.