title: Diet supplementation with cholic acid promotes intestinal epithelial proliferation in rats exposed to γ-radiation.
abstract: Consumption of a high-fat diet increases some secondary bile acids (BAs) such as deoxycholic acid (DCA) in feces. DCA is derived from cholic acid (CA), a primary BA. We evaluated intestinal epithelial proliferation and BA metabolism in response to oral administration of cholic acid (CA) in rats to determine the influence of a CA diet on the responses of gut epithelia to γ-rays. WKAH/HkmSlc rats were divided into two dietary groups: control diet or CA-supplemented (2g/kg diet) diet. Some of the rats from each group were irradiated with γ-rays, and epithelial cell proliferation in the colon was analyzed histochemically. Unirradiated CA-fed rats had high levels of DCA and CA in the sera, as well as the presence of taurocholic acid in their feces. Significant increases were observed in both epithelial proliferation and the number of epithelial cells in the colon of the CA-fed rats, and this effect was observed at 8 weeks after γ-ray exposure. Furthermore, extracts from both cecal contents and sera of the unirradiated CA-fed rats promoted proliferation of IEC-6 cells. These results indicate that BAs in enterohepatic circulation promote proliferation and survival of the intestinal epithelium after receiving DNA damage.
authors.affiliation: Division of Applied Bioscience, Research Faculty of Agriculture, Hokkaido University, Sapporo 060-8589, Japan; Faculty of Life Sciences, Toyo University, Ora, Gunma 374-0193, Japan.
authors.forename: Masahito
authors.initials: M
authors.lastname: Hagio
authors.affiliation: Division of Applied Bioscience, Research Faculty of Agriculture, Hokkaido University, Sapporo 060-8589, Japan.
authors.forename: Hidehisa
authors.initials: H
authors.lastname: Shimizu
authors.affiliation: Division of Applied Bioscience, Research Faculty of Agriculture, Hokkaido University, Sapporo 060-8589, Japan.
authors.forename: Ga-Hyun
authors.initials: GH
authors.lastname: Joe
authors.affiliation: Division of Applied Bioscience, Research Faculty of Agriculture, Hokkaido University, Sapporo 060-8589, Japan.
authors.forename: Manami
authors.initials: M
authors.lastname: Takatsuki
authors.affiliation: Division of Applied Bioscience, Research Faculty of Agriculture, Hokkaido University, Sapporo 060-8589, Japan.
authors.forename: Maiko
authors.initials: M
authors.lastname: Shiwaku
authors.affiliation: Division of Applied Bioscience, Research Faculty of Agriculture, Hokkaido University, Sapporo 060-8589, Japan; School of Food Science and Chemical Engineering, Beijing Technology and Business University, Beijing 100048, China.
authors.forename: Hong
authors.initials: H
authors.lastname: Xu
authors.affiliation: Division of Applied Bioscience, Research Faculty of Agriculture, Hokkaido University, Sapporo 060-8589, Japan.
authors.forename: Ja-Young
authors.initials: JY
authors.lastname: Lee
authors.affiliation: Division of Applied Bioscience, Research Faculty of Agriculture, Hokkaido University, Sapporo 060-8589, Japan.
authors.forename: Nobuyuki
authors.initials: N
authors.lastname: Fujii
authors.affiliation: Division of Applied Bioscience, Research Faculty of Agriculture, Hokkaido University, Sapporo 060-8589, Japan.
authors.forename: Satoru
authors.initials: S
authors.lastname: Fukiya
authors.affiliation: Division of Applied Bioscience, Research Faculty of Agriculture, Hokkaido University, Sapporo 060-8589, Japan.
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Hara
authors.affiliation: Division of Applied Bioscience, Research Faculty of Agriculture, Hokkaido University, Sapporo 060-8589, Japan.
authors.forename: Atsushi
authors.initials: A
authors.lastname: Yokota
authors.affiliation: Division of Applied Bioscience, Research Faculty of Agriculture, Hokkaido University, Sapporo 060-8589, Japan. Electronic address: zuka@chem.agr.hokudai.ac.jp.
authors.forename: Satoshi
authors.initials: S
authors.lastname: Ishizuka
mesh_terms: D000818:Animals; D017209:Apoptosis / Q000187:drug effects / Q000528:radiation effects; D002460:Cell Line; D049109:Cell Proliferation / Q000187:drug effects* / Q000528:radiation effects*; D019826:Cholic Acid / Q000008:administration & dosage*; D003106:Colon / Q000187:drug effects* / Q000473:pathology / Q000528:radiation effects*; D019587:Dietary Supplements; D004307:Dose-Response Relationship, Radiation; D004764:Enterohepatic Circulation; D004847:Epithelial Cells / Q000187:drug effects* / Q000473:pathology / Q000528:radiation effects*; D005243:Feces / Q000737:chemistry; D005720:Gamma Rays; D007413:Intestinal Mucosa / Q000187:drug effects* / Q000473:pathology / Q000528:radiation effects*; D007700:Kinetics; D008297:Male; D051381:Rats
chemical_list: D019826:Cholic Acid
keywords: Bile acid; Cecal contents; IEC-6 cells; Intestinal epithelial kinetics; Ultra performance liquid chromatography-electrospray ionization mass spectrometry; γ-rays