Cereals are important foods in refeeding of malnourished infants (M) but salivary and pancreatic amylase activities are often suppressed. We therefore studied the alternate starch hydrolase, jejunal maltase-glucoamylase (MGA). Our objective was to determine the specific activity (SA) and message for jejunal MGA in M. We recently reported the cloning of human MGA cDNA (Nichols et al, J. Biol. Chem. 1997, in press). The jejunal biopsies were obtained from 10 M referred for poor response to refeeding and from 6 nutritional (N) controls with biliary atresia at surgery. MGA and sucrase-isomaltase (SIM) enzyme activities were assayed by Dahlqvist and mRNA(m) by RT/PCR methods (0-4+). Villus atrophy was measured by morphology (1-4+) and mvillin. Malnutrition was assessed by weight/height SD below normal (WHZ). We conclude that the reduction of MGA activity and message in M is not a transcriptional suppression as with lactase-phlorizin hydrolase (Nichols et al, Gastroenterology 112:742-751, 1997), but an epigenetic change due to villus atrophy, identical to SIM. Table

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