Loop diuretic-induced increase in distal tubule sodium reabsorption

Diuretic responsiveness in patients previously treated with placebo or the loop diuretic furosemide. The subjects who had been treated with furosemide had a lesser increase in FENa after the administration of furosemide (left panel) but a greater natriuretic response to the addition of chlorothiazide (right panel). These findings are compatible with increased tubular sodium reabsorption at the thiazide-sensitive site in the distal tubule when distal sodium delivery is chronically increased by furosemide.