title: Disaccharidase activity in the small intestine of susceptible and resistant mice after primary and challenge infections with Giardia muris.
abstract: The activities of four disaccharidases were examined in resistant (C57Bl/6) and susceptible (C3H/HeN) mice during the primary infection with Giardia muris and after challenge with either trophozoite extract or cysts. Significant decreases in lactase, sucrase, trehalase, and maltase activities in C57Bl/6 mice and lactase and sucrase activities in C3H/HeN mice in the anterior 25% of the small intestine were observed on day 10 after infection. The activities of maltase, sucrase, trehalase, and lactase in the jejunum of C3H/HeN mice were significantly reduced after challenge with trophozoite extract, when compared with the uninfected or infected, but not challenged animals. Decreases in enzyme activities of C3H/HeN mice were evident as early as 12 hours after challenge with the extract. The resistant C57Bl/6 mice showed little change in disaccharidase activity after challenge with trophozoite extract. On the other hand, challenge with cysts resulted in a few decreases in disaccharidase activities in both strains of mice: C57Bl/6 mice showed decreases in the duodenum, while disaccharidases of C3H/HeN mice had lower activity more posteriorly. Thus, challenge with parasite antigen results in a more severe disaccharidase deficiency in susceptible hosts when compared with resistant ones.
authors.affiliation: Department of Zoology, University of Alberta, Edmonton, Canada.
authors.forename: C W
authors.initials: CW
authors.lastname: Daniels
authors.forename: M
authors.initials: M
authors.lastname: Belosevic
mesh_terms: D000818:Animals; D004186:Disaccharidases / Q000032:analysis*; D005243:Feces / Q000469:parasitology; D005260:Female; D005873:Giardiasis / Q000201:enzymology*; D007413:Intestinal Mucosa / Q000201:enzymology; D007421:Intestine, Small / Q000201:enzymology* / Q000469:parasitology; D043322:Lactase; D051379:Mice; D008809:Mice, Inbred C3H; D008810:Mice, Inbred C57BL; D013047:Specific Pathogen-Free Organisms; D013393:Sucrase / Q000032:analysis; D014198:Trehalase / Q000032:analysis; D000520:alpha-Glucosidases / Q000032:analysis; D001616:beta-Galactosidase / Q000032:analysis
chemical_list: D004186:Disaccharidases; D043322:Lactase; D000520:alpha-Glucosidases; D001616:beta-Galactosidase; D014198:Trehalase; D013393:Sucrase