Essential fatty acid deficiency and postresection mucosal adaptation in the rat

The effect of short-term (biochemical) and long-term (clinical) essential fatty acid (EFA) deficiency on mucosal adaptation was studied in a surgical model of short bowel syndrome. Rats fed an EFA-deficient diet for 4 wk had biochemical evidence of EFA deficiency (hepatic and red blood cell triene to tetraene ratios greater than 0.4). Resected animals (70% proximal jejunoileal resection) receiving an EFA-deficient diet had a significantly impaired intestinal mucosal hyperplasia response in all remaining small bowel segments compared with resected controls. The effect of refeeding a control diet to clinically EFA-deficient resected rats was also evaluated. Short-term refeeding (2 wk) of a control diet resulted in a significant return toward normal tissue triene to tetraene ratios. Concomitantly, refed animals had significantly greater mucosal adaptation in the remaining duodenal/jejunal segment compared with resected animals maintained on an EFA-deficient diet postoperatively. These experiments underscore the dynamic nature of tissue EFA status and the importance of fatty acids in the normal compensatory mechanisms of mucosal adaptation after resection.