Transport ATPases of cardiac sarcolemma in experimental uremia

Uremia was induced in rats and rabbits by unilateral nephrectomy and partial resection of the contralateral kidney. The effectiveness of the procedure was checked by determining serum urea levels that 7 days after operation were found to be more than twice as high in the operated than in the sham operated animals. Serum electrolytes at this time did not show significant alterations. In the cardiac sarcolemma from both kinds of animals the specific (Na+,K+)-ATPase activity was significantly decreased in the uremic animals. The basic, Mg2+-dependent ATPase was not affected.