Gossypol and Na+, K+ ATPase from human erythrocytes.

The inhibition of Na+, K+ ATPase by gossypol has been proposed as a mechanism for the hypokalemia occurring in some patients receiving this drug. Gossypol acetic acid, 3 microM (higher concentration than present clinically), did not inhibit this enzyme prepared from erythrocytes from 5 humans. Thus, it is unlikely that gossypol inhibition of the usual form of this enzyme is the mechanism for the initiation of the hypokalemia.