Renal excretion of ascorbic acid by dogs

¹ Department of Medicine, University of Florida College of Medicine, Gainesville, Florida

The renal excretion of ascorbic acid was evaluated in dogs by clearance experiments and stop-flow analyses. After stimulation of the distal sodium-potassium exchange mechanism with deoxycorticosterone acetate, clearance experiments revealed ascorbic acid-to-creatinine clearance ratios as high as 1.54. Stop-flow analyses revealed a distal secretory peak in the area of sodium-potassium exchange with U/P-to-U/P ratios as high as 1.3. These experiments demonstrate that secretion of ascorbic acid occurs in the distal tubule. Linkage with the distal sodium-potassium exchange and an effect of urine pH on tubular handling of ascorbic acid are postulated.

Key Words: kidney clearance • stop flow • proximal reabsorption • secretion • sodium • potassium • distal tubule

Submitted on October 14, 1964