title: Ingestion of potato starch containing esterified phosphorus increases alkaline phosphatase activity in the small intestine in rats.
abstract: Alkaline phosphatase (ALP) hydrolyzes a variety of monophosphate esters and plays an important role in phosphorus (P) metabolism. Several nutrients in food have been reported to affect intestinal ALP activity in animal models. Previous reports indicated that high levels of P or phosphate in diets decreased intestinal ALP activity in rats. Because potato starch contains considerable amounts of esterified P, unlike other starch-derived plants, we hypothesized that the feeding of potato starch would decrease ALP activity in the intestinal tract. Male Sprague-Dawley rats (7 weeks old) were fed 3 different types of diet containing 60% corn starch or 1 of 2 types of potato starch with different esterified P content for 1 or 5 weeks. Body weight and food intake of each rat were measured every day throughout the experimental periods. At the end of the feeding periods, the small intestine was removed to determine ALP activity in the mucosal tissues. Significant differences were observed in ALP activity in the small intestine between the 2 feeding periods, among the 4 segments of the small intestine, and among the 3 diet groups. Significant positive linear correlations between the amount of P derived from the starch and mucosal ALP activity were obtained in the jejunum and jejunoileum in rats after feeding for 5 weeks. We concluded, contrary to our hypotheses, that the ingestion of potato starch adaptively increases ALP activity in the upper part of the small intestine of growing rats in an esterified P content-dependent manner.
authors.affiliation: Faculty of Human Science, Hokkaido Bunkyo University, Eniwa, Hokkaido 061-1449, Japan. mineo@do-bunkyodai.ac.jp
authors.forename: Hitoshi
authors.initials: H
authors.lastname: Mineo
authors.forename: Nao
authors.initials: N
authors.lastname: Morikawa
authors.forename: Sayako
authors.initials: S
authors.lastname: Ohmi
authors.forename: Kyo
authors.initials: K
authors.lastname: Ishida
authors.forename: Ayaka
authors.initials: A
authors.lastname: Machida
authors.forename: Takumi
authors.initials: T
authors.lastname: Kanazawa
authors.forename: Hideyuki
authors.initials: H
authors.lastname: Chiji
authors.forename: Michihiro
authors.initials: M
authors.lastname: Fukushima
authors.forename: Takahiro
authors.initials: T
authors.lastname: Noda
mesh_terms: D000469:Alkaline Phosphatase / Q000378:metabolism*; D000818:Animals; D004951:Esterification; D007413:Intestinal Mucosa / Q000187:drug effects* / Q000201:enzymology; D007421:Intestine, Small / Q000187:drug effects* / Q000201:enzymology; D008297:Male; D016226:Phosphorus, Dietary / Q000008:administration & dosage*; D028321:Plant Preparations / Q000494:pharmacology*; D051381:Rats; D017207:Rats, Sprague-Dawley; D011198:Solanum tuberosum / Q000737:chemistry*; D013213:Starch / Q000494:pharmacology*; D003313:Zea mays / Q000737:chemistry
chemical_list: D016226:Phosphorus, Dietary; D028321:Plant Preparations; D013213:Starch; D000469:Alkaline Phosphatase