Sepsis increases putrescine concentration and protein synthesis in mucosa of small intestine in rats

Recent studies suggest that sepsis stimulates mucosal polyamine and protein synthesis. It is not known in which cell type polyamine biosynthesis is increased during sepsis and if polyamines regulate mucosal protein synthesis. We examined the effect of sepsis in rats on polyamine biosynthesis in isolated jejunal enterocytes and measured mucosal protein synthesis following inhibition of ornithine decarboxylase (ODC) activity with difluoromethylornithine. ODC and S-adenosylmethionine decarboxylase (SAMDC) activities and putrescine concentrations were increased in isolated jejunal enterocytes 16 h after induction of sepsis by cecal ligation and puncture. Enterocyte spermidine and spermine levels were not influenced by sepsis. Mucosal ODC and SAMDC activities and polyamine levels were increased following treatment of rats with interleukin-1 but not tumor necrosis factor. Treatment of rats with difluoromethylornithine prevented the sepsis-induced increase in mucosal ODC activity, putrescine concentration, and protein synthesis rate. The results suggest that sepsis increases ODC and SAMDC activities and putrescine concentrations in enterocytes of the small intestine. This metabolic response to sepsis may be regulated by interleukin-1 although other mechanisms may also be involved. Increased mucosal protein synthesis during sepsis may at least in part be regulated by increased putrescine levels.