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Spermidine acetyltransferase in rat hepatocytes cultured at different oxygen tensions
Author(s) -
Vargiu C,
Colombatto S,
Giribaldi G,
Grillo M A
Publication year - 1996
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.510240428
Subject(s) - spermidine , messenger rna , polyamine , acetyltransferase , oxygen , enzyme , putrescine , intracellular , biochemistry , hepatocyte , biology , chemistry , gene , in vitro , acetylation , organic chemistry
To understand the mechanism involved in the liver zonation of polyamines, we have studied the possible role of oxygen tension. When hepatocytes were cultured at 21% and at 5% oxygen in atmosphere to mimic periportal and perivenous conditions, polyamine content was modified. The observed modifications suggested an effect on the interconversion pathway. Spermidine acetyltransferase (SAT) activity and N 1 ‐acetylspermidine were therefore measured in the same conditions. SAT activity was markedly increased after 6 hours and N 1 ‐acetylspermidine was accumulated in the cells. This was caused by new enzyme synthesis. The higher expression of SAT was accompanied by an increase in the content of the specific messenger RNA (mRNA). When liver cells were depleted of polyamines, SAT activity and the specific mRNA content were not enhanced by oxygen deprivation, but they increased when polyamines were added again. Polyamines therefore appear to be necessary to promote the increase in SAT mRNA.