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Localization of Rat Small Intestine Glutamine Synthetase Using Immunofluorescence and In Situ Hybridization
Author(s) -
Roig J.C.,
Shenoy Vivek B.,
Chakrabarti Ratna,
Lau Johnson Y.N.,
Neu Josef
Publication year - 1995
Publication title -
journal of parenteral and enteral nutrition
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.935
H-Index - 98
eISSN - 1941-2444
pISSN - 0148-6071
DOI - 10.1177/0148607195019003179
Subject(s) - in situ hybridization , glutamine synthetase , in situ , immunofluorescence , glutamine , biology , biochemistry , chemistry , antibody , genetics , amino acid , gene , gene expression , organic chemistry
Glutamine is an important energy source for small intestinal epithelial enterocytes and serves as a key precursor for de novo synthesis of purines and pyrimidines in these rapidly dividing cells. Although glutamine synthetase (GS) is known to be the major enzyme of glutamine biosynthesis, the precise localization of this enzyme in the small intestine is not known. Because glutamine is an important precursor for nucleic acids biosynthesis, we hypothesized that GS is preferentially expressed in the crypt region, which contains the rapidly proliferating cells in the small intestine. Accordingly, immunofluorescence with a specific polyclonal antibody and in situ hybridization using a riboprobe were performed to localize GS protein and mRNA, respectively, in adult rats. Both GS protein and GS mRNA were detected primarily in the crypt region. This finding suggests that GS is located in the region with the highest nucleotide synthesis and cell proliferation. This finding is in support of the use of parenteral glutamine in patients with severe mucosal injury affecting the crypts. (Journal of Parenteral and Enteral Nutrition 19: 179–181, 1995)