EFFECT OF CHRONIC-RENAL-FAILURE ON THE ABUNDANCE OF MESSENGER-RNA FORENZYMES OF INTERMEDIARY METABOLISM IN KIDNEY AND LIVER

In chronic renal failure (CRF), renal ammoniagenesis and handling of o rnithine cycle intermediates (ornithine, citrulline, and arginine) are disturbed. The present study examined the molecular mechanisms of the se disturbances in kidney and liver of rats with moderate CRF induced by 5/6 nephrectomy. The steady state level of mRNA for phosphoenolpyru vate carboxykinase (PEPCK) and argininosuccinate synthetase (ASS) in b oth kidney and liver were unaffected by CRF. On the other hand, that f or phosphate-dependent glutaminase (PDG) was increased while that for ornithine decarboxylase (ODC) was decreased in the diseased kidney. Co mbined with previously reported enzymatic activities, our findings sug gest that, in CRF, gene expression is responsible for enzymatic change s of PDG and ODC, not of PEPCK and ASS. Underexpression of ODC, result ing in impaired renal polyamine synthesis, may contribute to progressi on of CRF. Finally, the significant increase in renal mRNA expression of p-actin precludes the use of this molecule as a reference in CRF.