The kidney plays a major role in arginine metabolism in 3 principal ways: arginine synthesis,
creatine synthesis, and arginine reabsorption. Appreciable quantities of arginine are
synthesized in the kidney from citrulline produced by the intestine. The renal enzymes of
arginine synthesis, argininosuccinate synthetase and argininosuccinate lyase, occur in the
cells of the proximal tubule. The rate of arginine synthesis depends on citrulline delivery and
does not appear to be regulated by dietary arginine availability. Renal arginine synthesis in …