Intestinal mast cell response in thymectomised and normal mice infected with Trichinella spiralis

In NIH mice, expulsion of Trichinella spiralis from the small intestine and increase in intestinal mast cells were each dependent on the presence of T-lymphocytes. Both changes were deficient in thymectomised mice but could be largely restored by reconstitution of thymectomised mice with syngenetic mesenteric lymph node cells. In both NIH and BALB/C mice the majority of the increased number of mast cells occurred within the intestinal epithelium. In NIH mice increase in the number of intestinal mast cells coincided roughly with expulsion of the parasites. In BALB/C mice increase in the numbers of intestinal mast cells did not appear to be connected with the location or expulsion of parasites and it is concluded that mast cell proliferation, accumulation and discharge per se do not result in or from worm expulsion.