Colocalization in pericentral hepatocytes in adult mice and similarity in developmental expression pattern of ornithine aminotransferase and glutamine synthetase mRNA
Journal
Proceedings of the National Academy of Sciences of the United States of America
Journal Volume
88
Journal Issue
21
Pages
9468-9472
Date Issued
1991
Author(s)
Abstract
In situ hybridization showed that the mRNA for ornithine aminotransferase (OAT; ornithine-oxo-acid aminotransferase; L-ornithine: 2-oxo-acid aminotransferase, EC 2.6.1.13) colocalized with glutamine synthetase [GS; glutamate-ammonia ligase; L-glutamate: ammonia ligase (ADP-forming), EC 6.3.1.2] in pericentral hepatocytes of the adult mouse liver. In addition to an identical distribution in adult hepatocytes, OAT and GS have very similar expression patterns in fetal and neonatal liver. As was earlier described for GS, there is a low level of OAT mRNA in fetal cells and increasing pericentral levels in neonates that reach adult patterns within 2 weeks. These results suggest that the transcriptional regulation of the two genes is similar in the liver. However, there was a lack of colocalization of the mRNAs for the two enzymes in cells of the kidney, intestine, and brain, suggesting different regulatory decisions for the OAT and GS genes in the cells of these different tissues. The metabolic consequences of these localized expression patterns favor ammonia clearance from the blood by the liver and urea synthesis by the kidney.
Publisher
National Academy of Sciences
Type
journal article