The Action of Ouabain on the Smooth Muscle Cells of the Rat Tail Artery 1

Summary

The transmembrane Na and K gradients of the smooth muscle cells of the rat tail artery are discharged about twice as fast in the absence of external K ions as in the presence of ouabain although a 1:1 exchange is involved in both cases. In large part, this observation reflects the fact that cell Na remains lower and cell K higher after prolonged incubation in a normal medium with maximal ouabain than in a K-free medium. These experiments still do not wholly exclude the possibility that changes in membrane permeability may also be involved.

The authors are indebted to Miss Maryette Mar for expert technical assistance.