Arginine Synthesis in Healthy Adult Humans

Arginine synthesis in mammals is a complex process involving at least 8 enzymes and intracellular and interorgan transfer of substrates. The investigators have shown in our neonatal studies that there is no conversion of glutamate to arginine but proline label appears in ornithine, citrulline and arginine. It is clear therefore that arginine is synthesized in human neonates from proline. In adults the source of the carbon backbone is less clear.