Effects of dietary menhaden oil on mucosal adaptation after small bowel resection in rats

Abstract

Adaptive hyperplasia of the small intestine is important in the outcome of short bowel syndrome. Previous studies have shown that long-chain fats stimulate this process. In the present study, the trophic effects of dietary menhaden oil, a highly unsaturated fat source, on mucosal adaptation following small bowel resection in rats was evaluated. Thirty weanling Sprague-Dawley rats and their controls were fed diets containing fats provided primarily as menhaden oil, safflower oil, or beef tallow. After 4 weeks, animals underwent a 70% jejunoileal resection. Mucosal mass, DNA, protein, and sucrase levels were assessed 14 days after a 70% jejunoileal resection or control feeding. Serum fatty acid composition and several gastrointestinal hormone levels were measured. Resected animals fed menhaden oil showed a marked increase in mucosal weight, DNA, and protein levels compared with rats fed the other fat sources. Enteroglucagon level was increased in all resected groups, but least increased in the menhaden-fed animals. In contrast, peptide YY concentrations were most increased in animals fed menhaden oil. Menhaden oil appears more effective in inducing intestinal adaptation than less highly unsaturated fats. Analysis of gastrointestinal hormones revealed no clear-cut explanation for this finding, other than a modest but associated increase in peptide YY levels.