Increased intestinal protein synthesis during sepsis and following the administration of tumour necrosis factor α or interleukin-1α

The influence of sepsis on intestinal protein synthesis was studied in rats. Sepsis was induced by caecal ligation and puncture (CLP); control rats were sham-operated. Protein synthesis was measured in vivo in the jejunum and ileum following a flooding dose of [¹⁴C]leucine. At 8h after CLP the protein synthesis rate was increased by approx. 15% in jejunal mucosa, and at 16h after CLP, the protein synthesis rate was increased by 50-60% in the mucosa and seromuscular layer of both jejunum and ileum. In a second series of experiments. rats were treated with recombinant tumour necrosis factor α (rTNFα) or recombinant interleukin-1α (rIL-1α) administered at a total dose of 300 μg/kg body weight over 16h. Control rats received corresponding volumes of solvent. Treatment with rTNFα resulted in an approx. 25% increase in mucosal protein synthesis in jejunum. Following treatment with rIL-1α, protein synthesis increased by 25% in jejunal mucosa and almost doubled in ileal mucosa. The results suggest that sepsis stimulates intestinal protein synthesis and that this response may, at least in part, be mediated by TNF and/or IL-1.