Na+-stimulated ATPase activities in kidney basal-lateral plasma membranes.
In the present work we demonstrate the existence of a Na+-dependent ATPase activity, which is insensitive to ouabain, and which is 100% inhibited by 1.5 mM ethacrynic acid in freshly prepared, basal-lateral enriched, plasma-membrane fractions obtained from guinea-pig kidney cortex slices (which are mainly made up by proximal tubules). This ATPase activity has characteristics similar to those described previously in a microsomal fraction of the guinea-pig kidney cortex by a procedure which required ageing of the preparation for more than two weeks (Proverbio, F., Condrescu-Guidi, M. and Whittembury, G. (1975) Biochim. Biophys. Acta 394, 281-292), it does not seem to be due to some partially modified activity of the Mg2+-ATPase, the (Na+ + K+)- or the Ca2+-ATPase activities present in this tissue. It seems to be due to the activity of another system, which is located on the basal-lateral membrane of the kidney tubular cells.
D000251:Adenosine Triphosphatases / Q000378:metabolism*; D000818:Animals; D002118:Calcium / Q000494:pharmacology; D002462:Cell Membrane / Q000201:enzymology; D003840:Deoxycholic Acid / Q000494:pharmacology; D004533:Egtazic Acid / Q000494:pharmacology; D004976:Ethacrynic Acid / Q000494:pharmacology; D006168:Guinea Pigs; D007672:Kidney Cortex / Q000201:enzymology*; D008274:Magnesium / Q000378:metabolism; D010042:Ouabain / Q000494:pharmacology; D012964:Sodium / Q000494:pharmacology*; D012974:Sodium Iodide / Q000494:pharmacology
D003840:Deoxycholic Acid; D004533:Egtazic Acid; D010042:Ouabain; D012964:Sodium; D000251:Adenosine Triphosphatases; D012974:Sodium Iodide; D008274:Magnesium; D004976:Ethacrynic Acid; D002118:Calcium