Influence of chronic acidosis on plasma glutamine and urea production in the nephrectomized rat.

WELBOURNE, TOMAS C. Influence of chronic acidosis on plasma glutamine and urea production in the nephrectomized rat. Am. J. Physiol. 224(4) : 796-802. 1973.-Nitrogen partition between glutamine and urea production in normal and chronic acidosis was investigated in bilaterally nephrectomized rats. Metabolic acidosis was induced by chronic administration of NH&l in one group and by administration of acetazolamide, as a control for exogenous nitrogen contained in NH&l loads, in a second group. Plasma glutamine and urea concentration were measured before and serially over 600 min after bilateral nephrectomy. Following nephrectomy, glutamine levels fell in both normal and chronically acidotic groups. On the other hand, plasma urea rose linearly over the 600-min observation period. The rate of rise was significantly greater in acidotic rats than in normal rats. Urea production by the chronically acidotic nephrectomized rats was greater than that of normal nephrectomized rats; furthermore, postnephrectomy urea production exceeded prenephrectomy rates only in chronically acidotic rats. These findings indicate accelerated urea production by chronically acidotic nephrectomized rats, which, in part, may result from a shift of nitrogen from glutamine to urea production.