01876naa a2200217 a 450000100080000000500110000800800410001910000150006024501540007526000090022952012230023865000100146165300190147165300130149065300220150370000140152570000150153970000190155470000180157377300670159115165771997-02-26       1996    bl uuuu     u00u1 u    #d1 aROY, E. A.  aDevelopment of morphological changes and ileal glucagon gene expression in the small intestine of lambs infected with Trichostrongylus colubriformis.  c1996  aTo investigate the consequences of subclinical Trichostrongylus colubriformis infection on the intestinal mucosa and the associated changes in enteroglucagon gene expression, sheep were infected with 30 000 larvae and killed 5, 10, 15 or 20 days after infection. Histological and cytological changes were examined. ln the main site of infection, the upper duodenum, villous atrophy associated with crypt hyperplasia developed gradually. Cytological changes in the enterocytes appeared concurrently, characterized by a progressive reduction in brush border and in the number of ribosomes in the cytoplasm, changes in the internaI structure of mitochoqdria, and enlargement of the interceilular spaces. Neither histological nor cytological modifications were found before clay 15. At the same time, villous hypertrophy deveioped distally, beyond the main site of infection; this was interpreted as an adaptive response to parasitism. Enteroglucagon gene expression in tbe ileum was measured in parallel with the mucosal changes but did not reveal any difference between infected and contrai sheep. The results indicate that this gastrointestinal hormone does not have a major foie in the response to nematode parasitism.  aOvino  aAntihelmintico  aControle  aEndoparasitologia1 aHOSTE, H.1 aFULLER, P.1 aTATARCZUCH, L.1 aBEVERIDGE, I.  tJournal of Comparative Pathologygv.115, n.4, p.441-453, 1996.