Effect of Na and impermeant anions on renal K transport during stopped flow

¹ Department of Physiology, University of Michigan, Ann Arbor, Michigan

The influence of increased urinary concentrations of NaCl and Na₂SO₄ upon the stop flow concentration patterns for potassium has been studied. Hypertonic NaCl and Na₂SO₄ solutions were infused into the renal artery of dogs before and during a period of stopped flow. The NaCl infusions increased the maximum concentration of potassium achieved during stopped flow but had no effect on the minimum concentrations reached. Na₂SO₄ infusions shifted the locus of the maximum concentrations of potassium to a more proximal location in the stop flow patterns whereas NaCl infusions did not. It is concluded that the minimum concentrations of potassium in the stop flow patterns are the result of increased reabsorption rather than decreased secretion due to a lack of sodium. The alteration in the pattern produced by Na₂SO₄ is due to the presence of the impermeant anion rather than increased sodium concentrations.

Note:
With the Technical Assistance of Michael McVaugh