BACKGROUND/AIMS: Developmental changes of lactase activity along the proximal-to-distal axis of the small intestine are poorly understood. A study of delineate lactase gene expression at the cellular level was undertaken. METHODS: The topographical regulation of lactase was studied in conjunction with sucrase-isomaltase in proximal, middle, and distal segments of 0-, 7-, 14-, 16-, 18-, 21-, and 28-day-old and adult rats using in sity hybridization, immunohistochemistry, and ribonuclease protection assays. RESULTS: From 0 to 16 days, lactase messenger RNA (mRNA) and protein were abundant along the total length of the small intestine. However, at weaning, lactase mRNA and protein were no longer detectable in the terminal ileum. After 28 days, zones of reduced lactase expression were found in the duodenum and terminal ileum. These zones demonstrated expression of lactase protein in scattered enterocytes along the villus (patchy expression). In contrast, sucrase-isomaltase was first detected at 16 days, with patchy expression along the total small intestine; at 21 days it was abundant. CONCLUSIONS: Concordant changes in both lactase mRNA and protein detection during development suggest that the horizontal gradient of lactase enzyme expression is dependent on lactase mRNA abundance. Furthermore, zones of patchy lactase expression appear around weaning and flank the area of high lactase expression in the midintestine. Patchy expression is also found for sucrase-isomaltase before weaning.
BACKGROUND/AIMS: Developmental changes of lactase activity along the proximal-to-distal axis of the small intestine are poorly understood. A study of delineate lactase gene expression at the cellular level was undertaken. METHODS: The topographical regulation of lactase was studied in conjunction with sucrase-isomaltase in proximal, middle, and distal segments of 0-, 7-, 14-, 16-, 18-, 21-, and 28-day-old and adult rats using in sity hybridization, immunohistochemistry, and ribonuclease protection assays. RESULTS: From 0 to 16 days, lactase messenger RNA (mRNA) and protein were abundant along the total length of the small intestine. However, at weaning, lactase mRNA and protein were no longer detectable in the terminal ileum. After 28 days, zones of reduced lactase expression were found in the duodenum and terminal ileum. These zones demonstrated expression of lactase protein in scattered enterocytes along the villus (patchy expression). In contrast, sucrase-isomaltase was first detected at 16 days, with patchy expression along the total small intestine; at 21 days it was abundant. CONCLUSIONS: Concordant changes in both lactase mRNA and protein detection during development suggest that the horizontal gradient of lactase enzyme expression is dependent on lactase mRNA abundance. Furthermore, zones of patchy lactase expression appear around weaning and flank the area of high lactase expression in the midintestine. Patchy expression is also found for sucrase-isomaltase before weaning.
Authors: Jay V Patankar; Prakash G Chandak; Sascha Obrowsky; Thomas Pfeifer; Clemens Diwoky; Andreas Uellen; Wolfgang Sattler; Rudolf Stollberger; Gerald Hoefler; Akos Heinemann; Michele Battle; Stephen Duncan; Dagmar Kratky; Sanja Levak-Frank Journal: Am J Physiol Endocrinol Metab Date: 2010-12-21 Impact factor: 4.310
Authors: Barbara Vanhoecke; Emma Bateman; Bronwen Mayo; Eline Vanlancker; Andrea Stringer; Daniel Thorpe; Dorothy Keefe Journal: Exp Biol Med (Maywood) Date: 2015-05-12
Authors: Edward Oh; Richie Jeremian; Gabriel Oh; Daniel Groot; Miki Susic; KwangHo Lee; Kelly Foy; Peter W Laird; Arturas Petronis; Viviane Labrie Journal: Sci Rep Date: 2017-01-31 Impact factor: 4.379
Authors: Marit Navis; Tânia Martins Garcia; Ingrid B Renes; Jacqueline Lm Vermeulen; Sander Meisner; Manon E Wildenberg; Gijs R van den Brink; Ruurd M van Elburg; Vanesa Muncan Journal: EMBO Rep Date: 2018-12-10 Impact factor: 8.807