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Developmental appearance of ammonia‐metabolizing enzymes in prenatal murine liver
Author(s) -
Notenboom Robbert G.E.,
Moorman Antoon F.M.,
Lamers Wouter H.
Publication year - 1997
Publication title -
microscopy research and technique
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.536
H-Index - 118
eISSN - 1097-0029
pISSN - 1059-910X
DOI - 10.1002/(sici)1097-0029(19971201)39:5<413::aid-jemt4>3.0.co;2-h
Subject(s) - glutamine synthetase , glutamate dehydrogenase , biology , enzyme , glutamine , microbiology and biotechnology , medicine , glutamate receptor , biochemistry , amino acid , receptor
To resolve an apparent discrepancy in the developmental appearance of glutamine synthetase (GS) protein in rat [Gaasbeek Janzen et al. (1987) J. Histochem. Cytochem., 35:49–54] and mouse [Bennett et al. (1987) J. Cell Biol., 105:1073–1085] liver, we have investigated its expression during liver development in the mouse and compared it with that of carbamoylphosphate synthetase I (CPS). The expression of glutamate dehydrogenase was used as a marker to identify all hepatocytes in these strongly hematopoietic livers. GS protein accumulation starts in mouse hepatocytes at embryonic day (ED) 15. The first hepatocytes in which the enzyme accumulates were found around the major hepatic veins. CPS protein was found to accumulate in mouse hepatocytes from ED 13 onward: first, at the center of the median and lateral lobes, but temporarily not at the periphery of these lobes and not at the caudate lobe. The initial phase of accumulation of GS and CPS protein was characterized by a heterogeneity in enzyme content between hepatocytes. By ED 17, both enzymes were detectable in all hepatocytes at the center of the median and lateral lobes. This event marked the onset of the development of the complementary distribution of the enzymes typical of zonal heterogeneity in the adult mammalian liver. However, during the perinatal period, the pericentral hepatocytes temporarily accumulated CPS protein. We also observed heterochrony between species in the appearance of CPS protein in the small intestine. Microsc. Res. Tech. 39:413–423, 1997. © 1997 Wiley‐Liss, Inc.