Indoleamine-Pyrrole-2,3-Dioxygenase-l Is Over-Expressed and Negatively Correlated with Serum Tryptophan Concentrations in Dogs with Protein-Losing Enteropathy

摘要

Indoleamine-pyrrole 2,3-dioxygenase (IDO-1) is the initial rate-limiting step in the pathway for the oxidation of tryptophan to kynurenine. IDO-1 expression is increased in the gastrointestinal tract of humans with inflammatory bowel disease (IBD) dueto over-expression of proinflammatory cytokines and over activation of toll-like receptors. This increased IDO-1 expression is associated with lower serum tryptophan concentrations in human IBD dtte to increased tryptophan catabolism. Dogs with protein-losing enteropathy (PLE) have decreased serum tryptophan concentrations compared to apparently healthy dogs. However, IDO-1 expression has not been previously assessed in the intestinal mucosa of dogs with PLE. Therefore, this study aimed to determine if there was a significant difference in mRNA expression of IDO-1 in the duodenal mucosa of dogs with PLE compared to healthy dogs and whether this expression correlated with serum tryptophan concentrations in dogs with PLE.