Spermidine acetyltransferase in rat hepatocytes cultured at different oxygen tensions

✍ Scribed by C Vargiu; S Colombatto; G Giribaldi; M A Grillo

• Publisher: John Wiley and Sons
• Year: 1996
• Tongue: English
• Weight: 229 KB
• Volume: 24
• Category: Article
• ISSN: 0270-9139
• DOI: 10.1002/hep.510240428

✦ Synopsis

and perivenous conditions, polyamine content was modified.

To understand the mechanism involved in the liver

The modification was higher for spermidine than for putreszonation of polyamines, we have studied the possible cine, suggesting an effect on the interconversion pathway role of oxygen tension. When hepatocytes were cultured (Fig. 1). N 1 -acetylspermidine and spermidine acetyltransferat 21% and at 5% oxygen in atmosphere to mimic periporase (SAT) activity were therefore measured in the same contal and perivenous conditions, polyamine content was ditions at different incubation times. The results obtained modified. The observed modifications suggested an efare reported in this article. fect on the interconversion pathway. Spermidine acetyltransferase (SAT) activity and N 1 -acetylspermidine were MATERIALS AND METHODS therefore measured in the same conditions. SAT activity Materials. 1-[ 14 C]Ornithine, 1-[ 14 C]S-adenosylmethionine, 14 C-acetylwas markedly increased after 6 hours and N 1 -acetylspercoenzyme A and [a-32 P]deoxycytidine 5-[a-32 P]triphosphate were midine was accumulated in the cells. This was caused from Amersham (Little Chalfont, Buckinghamshire, UK); horse seby new enzyme synthesis. The higher expression of SAT rum, penicillin/streptomycin, and M199 were from Flow Laboratories was accompanied by an increase in the content of the (Irvine Ayrshire, Scotland); collagenase, bovine serum albumin, and specific messenger RNA (mRNA). When liver cells were spermidine were from Sigma Chemical Co. (St. Louis, MO). Human depleted of polyamines, SAT activity and the specific SAT complementary DNA was a generous gift from Dr. R. Casero, mRNA content were not enhanced by oxygen depriva-