Open AccessMosaic Expression of Brush-Border Enzymes in Infants with Chronic Diarrhea and Malnutrition
Author(s) -
Buford L. Nichols,
Francisco Roque Carrazza,
Veda N. Nichols,
Margaret Putman,
Pamela Johnston,
Maraci Rodrigues,
Andrea Quaroni,
Margot Shiner
Publication year - 1992
Publication title -
journal of pediatric gastroenterology and nutrition
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.206
H-Index - 131
eISSN - 1536-4801
pISSN - 0277-2116
DOI - 10.1097/00005176-199205000-00002
Subject(s) - brush border , sucrase , lactase , maltase , disaccharidase , medicine , intestinal mucosa , pathogenesis , aminopeptidase , diarrhea , alkaline phosphatase , enzyme , pathology , biology , immunology , small intestine , biochemistry , amino acid , membrane , vesicle , leucine
The chronic diarrhea observed in young malnourished infants that is sensitive to dietary glucose and other carbohydrates is associated with variable degrees of patchy mucosal villous atrophy. To explore intrinsic mucosal function in the pathogenesis of this alimentary intolerance, we have conducted an immunohistologic investigation of brush-border enzyme proteins of clinically obtained, mucosal biopsy samples. We used a group of monoclonal antibodies against human brush-border aminopeptidase, sucrase/isomaltase (SI), maltase, and lactase enzyme proteins. SI was strongly and uniformly expressed in crypts and villi of 11 of the 14 subjects; in 3 subjects, however, SI was expressed in a mosaic pattern. Maltase and lactase were occasionally absent, but more commonly were expressed in a mosaic distribution. The mosaic expression of brush-border enzyme proteins has been reported in congenital enzyme deficiencies associated with normal intestinal histology. We report the mosaic expression of brush-border enzyme proteins as a functional alteration associated with a pathological lesion of the mucosa in infants with chronic diarrhea. Our observation challenges the existing concept of ontogenic regulation of brush-border enzyme activity.