Effect of sodium bicarbonate and Tris (THAM) infusion on intra- and extracellular acid-base status during experimental uremia in the rat.

Abstract

The intra- and extracellular acid-base status of nephrectomized rats was determined following infusion of 10 mmol/kg body mass Tris (THAM) or sodium bicarbonate. The 'mean whole body pHi', an overall estimate of the intracellular pH (complementary to the in vivo determined arterial plasma pH) was calculated from the distribution of 14C-labelled 5,5-dimethyl-2,4-oxazolidinedione. For evaluation of buffer effect of Tris or sodium bicarbonate, extra- and intracellular bicarbonate concentration was calculated from the Henderson-Hasselbalch equation. Intracellular and extracellular pH and bicarbonate concentration were significantly more increased when sodium bicarbonate was infused, while PCO2 increased significantly more when Tris was administered. On the basis of these results it is concluded that treatment of both in intracellular and extracellular uremic acidosis can be performed more efficiently with bicarbonate than with Tris buffer.