Inhibition of (Na+K+)-ATPase and cation transport by an antibody against renal plasma membranes.
An antibody was raised in rabbits against NaI extracted plasma membranes of rat kidney. The antibody inhibited (Na+K+)-ATPase of basolateral membranes and of rat erythrocyte ghosts. Also K+-stimulated pNPase was inhibited. No effect on Mg-ATPase and basal pNPase activity was registered. Kinetic experiments with Na+,K+ and Mg-ATP showed a noncompetitive inhibition of (Na+K+)-ATPase by the antibody. Hill constants were unchanged. In renal epithelial cell cultures as well as in intact rat erythrocytes ouabain sensitive 22Na-efflux and 42K influx was inhibited by the antibody. It is concluded that outward facing Na+K+-ATPase is immunogenic. The antibody can be raised when the antigen is adequately disintegrated to open otherwise hidden antigenic sites.
D000818:Animals; D001692:Biological Transport / Q000187:drug effects; D001693:Biological Transport, Active / Q000187:drug effects; D002462:Cell Membrane / Q000276:immunology*; D004912:Erythrocytes / Q000187:drug effects / Q000378:metabolism; D007074:Immunoglobulin G; D007672:Kidney Cortex / Q000378:metabolism*; D007700:Kinetics; D008297:Male; D010042:Ouabain / Q000494:pharmacology; D011188:Potassium / Q000378:metabolism / Q000494:pharmacology; D051381:Rats; D012964:Sodium / Q000378:metabolism / Q000494:pharmacology; D000254:Sodium-Potassium-Exchanging ATPase / Q000037:antagonists & inhibitors*
D007074:Immunoglobulin G; D010042:Ouabain; D012964:Sodium; D000254:Sodium-Potassium-Exchanging ATPase; D011188:Potassium