Abstract
ABSTRACT: Circulating arginine available for synthesis of protein is produced in the kidney of the adult mammal by the action of the last two enzymes of the urea cycle, argininosuccinate synthase and argininosuccinate lyase. In a previous publication, we reported the presence of a complete biosynthetic pathway for arginine in the intestine of the neonatal mouse at a time when no other endogenous sources of arginine were available. Our present study was aimed at the determination of the source of ornithine used by the intestine of the neonatal mouse for the synthesis of arginine. We established the developmental profile of the two intestinal mitochondrial enzymes, pyrroline 5-carbox-ylate synthase and ornithine aminotransferase, responsible for the conversion of glutamate to ornithine. Both enzymatic activities were found to be significantly elevated throughout the suckling period with a peak of activity during the 2nd wk of life. Glutamate dehydrogenase activity in the intestine did not appear to be developmentally regulated during the suckling and weaning periods; therefore, this enzyme was used as a convenient marker to quantify mitochondrial preparations. Ornithine decarboxylase activity was undetectable in the intestine of the mouse during the suckling period and was detected briefly at weaning, indicating that ornithine synthesized in the intestinal mitochondria is probably not diverted actively into the polyamine pathway and is available for synthesis of arginine by the enzymes of the urea cycle.
Similar content being viewed by others
Article PDF
Author information
Authors and Affiliations
Rights and permissions
About this article
Cite this article
Riby, J., Hurwitz, R. & Kretchmer, N. Development of Ornithine Metabolism in the Mouse Intestine. Pediatr Res 28, 261–265 (1990). https://doi.org/10.1203/00006450-199009000-00022
Received:
Accepted:
Issue Date:
DOI: https://doi.org/10.1203/00006450-199009000-00022
This article is cited by
-
The proline biosynthesis in living organisms
Amino Acids (1997)
-
Mice lacking ornithine–δ–amino–transferase have paradoxical neonatal hypoornithinaemia and retinal degeneration
Nature Genetics (1995)