title: Potato extract (Potein) suppresses food intake in rats through inhibition of luminal trypsin activity and direct stimulation of cholecystokinin secretion from enteroendocrine cells.
abstract: Dietary proteins and trypsin inhibitors are known to stimulate the secretion of the satiety hormone cholecystokinin (CCK). A potato extract (Potein) contains 60% carbohydrate and 20% protein including trypsin inhibitory proteins. In this study, we examined whether Potein suppresses food intake in rats and whether it directly stimulates CCK secretion in enteroendocrine cells. In fasted rats, food consumption was measured up to 6 h after the oral administration of Potein or soybean trypsin inhibitor (SBTI). CCK-releasing activities of Potein and SBTI were examined in the murine CCK-producing cell line STC-1. Potein inhibited the trypsin activity in vitro with a potency 20-fold lower than that of SBTI. Oral administration of Potein dose-dependently suppressed food intake for 1-6 h. Potein, but not the SBTI, dose-dependently induced CCK secretion in STC-1 cells. These results suggest that Potein suppresses food intake through the CCK secretion induced by direct stimulation on enteroendocrine cells and through inhibition of luminal trypsin.
authors.affiliation: Division of Applied Biosciences, Graduate School of Agriculture, Hokkaido University, Kita-9, Nishi-9, Kita-ku, Sapporo 060-8589, Japan.
authors.forename: Shingo
authors.initials: S
authors.lastname: Nakajima
authors.forename: Tohru
authors.initials: T
authors.lastname: Hira
authors.forename: Masahito
authors.initials: M
authors.lastname: Tsubata
authors.forename: Kinya
authors.initials: K
authors.lastname: Takagaki
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Hara
mesh_terms: D000818:Animals; D002460:Cell Line; D002766:Cholecystokinin / Q000378:metabolism*; D004435:Eating / Q000187:drug effects*; D019858:Enteroendocrine Cells / Q000187:drug effects* / Q000378:metabolism; D008297:Male; D010936:Plant Extracts / Q000494:pharmacology; D010940:Plant Proteins / Q000494:pharmacology*; D051381:Rats; D017207:Rats, Sprague-Dawley; D012527:Satiation / Q000187:drug effects; D011198:Solanum tuberosum / Q000737:chemistry*; D014361:Trypsin Inhibitors / Q000494:pharmacology*
chemical_list: D010936:Plant Extracts; D010940:Plant Proteins; D014361:Trypsin Inhibitors; D002766:Cholecystokinin