The intestinal profile of Na-K-ATPase in three rat models of acute renal failure.

The specific activity of mucosal Na-K-ATPase in segments of the small intestine and colon was examined after bilateral nephrectomies (BN), bilateral upper ureteral ligations (BUUL) and bilateral lower ureteral ligations (BLUL). Animals were studied 22-26 h after these respective operations. Bilateral nephrectomies and bilateral upper ureteral ligations resulted in an increase of the specific activity of the enzyme throughout the mucosa of the intestinal tract. Bilateral lower ureteral ligations induced no significant change in the specific activity of Na-K-ATPase in the intestinal mucosa. There were no differences in the degree of renal failure. Marked aldosteronemia was observed in the BN and the BUUL rats but not in the BLUL rats. These data suggest that the increase in the intestinal Na-K-ATPase activity in the BN and the BUUL rats may be related to the elevation of serum aldosterone as a regulator of the body potassium.