Intestinal regrowth is amplified after jejunal but not real resection during tapeworm infection in the rat

The ileum possesses functions required by a healthy individual that are not fully supplanted by the duodenum or jejunum. Evidence suggests that the il eum may also be necessary to maintain an enteric parasite-host interaction. We hypothesized that the ileum is essential to the survival of the lumen-d welling, rat tapeworm, H. diminuta. Male rats were divided into three group s: those with ileal or jejunal resections and nonresected controls. Half of each rat group was infected with the tapeworm. After jejunal resection, th e weight but not length of intestinal remnant (duodenum + ileum) in infecte d rats returned to that of control, nonresected intestine 29 days after sur gery and tapeworm numbers were fully maintained. In contrast, after ileal r emoval intestinal length and weight of the remaining duodenum and jejunum i n infected rats were significantly decreased and tapeworm survival diminish ed. Data indicates that intestinal growth following resection is amplified by tapeworm infection when the ileum remains but diminished when the ileum is removed. Furthermore, loss of the ileum results in decreased infection i ntensity and dry weight of the tapeworm.