RENAL CATABOLISM OF EXOGENOUS OXYNTOMODULIN IN RATS

The renal catabolism of oxyntomodulin has been studied both in vivo, b y the disappearance of exogenous [I-125] oxyntomodulin from the plasma of normal, bilateral ureter-ligated and bilaterally nephrectomized ra ts, and also in vitro, analyzing the degradation of the iodinated pept ide by the rat isolated renal tubules. Results from in vivo studies de monstrated that the urinary excretion of [I-125] oxyntomodulin was neg ligible, and that the metabolic clearance rate of the peptide was high er in normal rats than in the other two groups of animals, whereas no difference between the latter were found. Isolated tubules produced a degradation of the peptide proportional to tubules concentration. It c an be concluded that the kidney plays a role in the catabolism of oxyn tomodulin and that it occurs by a mechanism that involves glomerular f iltration and tubular degradation.