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Hepatocytes explanted in the spleen preferentially express carbamoylphosphate synthetase rather than glutamine synthetase
Author(s) -
Lamers Wouter H.,
Been Willem,
Charles Robert,
Moorman Antoon F. M.
Publication year - 1990
Publication title -
hepatology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 5.488
H-Index - 361
eISSN - 1527-3350
pISSN - 0270-9139
DOI - 10.1002/hep.1840120414
Subject(s) - glutamine synthetase , spleen , glutamine , chemistry , biochemistry , microbiology and biotechnology , biology , immunology , amino acid
Urea cycle enzymes and glutamine synthetase are essential for NH 3 detoxification and systemic pH homeostasis in mammals. Carbamoylphosphate synthetase, the first and flux‐determining enzyme of the cycle, is found only in a large periportal compartment, and glutamine synthetase is found only in a small, complementary pericentral compartment. Because it is not possible to manipulate experimentally the intrahepatic distribution of carbamoylphosphate synthetase and glutamine synthetase, we looked for conditions in which explanted hepatocytes would exhibit either the carbamoylphosphate synthetase phenotype or glutamine synthetase phenotype. In the spleen hepatocytes either settle as individual cells or in small agglomerates. The dispersed cells only express the carbamoylphosphate synthetase phenotype. Within the agglomerates, sinusoids that drain on venules develop. Hepatocytes surrounding the venules stain only weakly for carbamoylphosphate synthetase but are strongly positive for glutamine synthetase. These observations were made for explanted embryonic hepatocytes (no prior expression of either carbamoylphosphate synthetase or glutamine synthetase), neonatal hepatocytes (compartments of gene expression not yet established) and adult periportal and pericentral hepatocytes. (HEPATOLOGY 1990;12:701–709).