Effect of ouabain upon erythrocyte membrane adenosine triphosphatase in Duchenne muscular dystrophy.

The adenosine triphosphatase activity of erythrocyte ghosts from patients with Duchenne muscular dystrophy was inhibited by 10(-4) M ouabain to a smaller extent than in normals, when measured in the presence of either high or low concentrations of sodium or potassium ions. The inhibition by ouabain of the enzyme in normal ghosts, measured with low sodium or potassium ions, was less if the erythrocytes were first incubated with plasma from Duchenne patients than if incubated with normal plasma. Similar results were obtained when the ghosts themselves were incubated with Duchenne or normal plasma before assay.