The in vitro intestinal absorption of enterostatin is limited by brush-border membrane peptidases.
The intestinal metabolism and absorption of enterostatin was studied using brush-border membrane vesicles and an in vitro model of intestinal segments from rabbit ileum mounted in Sweetana-Grass diffusion chamber. Hydrolysis of enterostatin was observed with both epithelial sheets and brush-border membranes. The main metabolite was found to be des-arginine-enterostatin. Dipeptidylpeptidase IV was found to play a minor role in enterostatin degradation, whereas carboxypeptidase P activity accounted for the initial step of peptide hydrolysis. More than 50% of the amount of enterostatin added to the mucosal compartment of the Sweetana-Grass diffusion chamber was degraded after 30 min. Enterostatin was mainly absorbed as degradation products but a small transepithelial passage of des-arginine-enterostatin and immunoreactive enterostatin was also detected. Although immunoreactive enterostatin exhibits a low apparent permeability coefficient in rabbit ileum, the luminal production of this peptide may be of physiological importance in the control of appetite.
Huneau
J F
JF
INRA, Unité de Nutrition Humaine et Physiologie Intestinale, Faculté de Pharmacie, Paris, France.
Erlanson-Albertsson
C
C
Beauvallet
C
C
Tomé
D
D
D000595:Amino Acid Sequence; D000818:Animals; D002851:Chromatography, High Pressure Liquid; D003089:Colipases / Q000378:metabolism*; D004594:Electrophysiology; D010450:Endopeptidases / Q000378:metabolism*; D004792:Enzyme Precursors; D066298:In Vitro Techniques; D007408:Intestinal Absorption; D008297:Male; D008871:Microvilli / Q000201:enzymology*; D008969:Molecular Sequence Data; D011498:Protein Precursors / Q000378:metabolism*; D011817:Rabbits
D003089:Colipases; D004792:Enzyme Precursors; D011498:Protein Precursors; C037107:procolipase; D010450:Endopeptidases