MICROPUNCTURE STUDIES ON THE MECHANISM OF SULFATE EXCRETION BY THE RAT KIDNEY
ARMY AEROMEDICAL RESEARCH LAB FORT RUCKER AL
Pagination or Media Count:
A series of free flow micropuncture experiments were performed on rats undergoing sodium sulfate diuresis. End proximal tubular fluids and ureteral urines from the punctured kidney were collected. The data indicates that tubular fluidplasma TFP ratios for sulfate remained close to 1.0 and filtrate reabsorption was quantitatively normal during sulfate infusion in the proximal tubule. Final urine analysis suggested that all sulfate leaving the proximal convolution is excreted. The data is interpreted as evidence that sulfate is not handled by a TM limited mechanism in the rat kidney. Rather it appears dependent upon filtration rate, proximal tubular reabsorptive rate and plasma concentration of the anion. A comparison of bicarbonate reabsorption during carbonic anhydrase inhibition to sulfate reabsorption in the rat nephron suggests greater proximal passive permeability to sulfate than bicarbonate and equally restricted distal nephron permeability.
- Anatomy and Physiology