title: Passive and carrier-mediated intestinal absorption components of two angiotensin converting enzyme (ACE) inhibitor prodrugs in rats: enalapril and fosinopril.
abstract: The intestinal absorption mechanism of two ACE inhibitor prodrugs, enalapril and fosinopril, was investigated in rats using a single-pass perfusion method. A modified boundary layer solution was applied to determine the apparent intestinal wall permeability. The prodrug enalapril is well absorbed from rat jejunum, whereas the parent drug, enalaprilat, is poorly absorbed. The permeability of enalapril is concentration dependent and is decreased by the dipeptide Tyr-Gly and by cephradine but not by the amino acids L-leucine or L-phenylalanine, indicating a nonpassive absorption mechanism via the small peptide carrier-mediated transport system. In contrast, fosinopril is readily absorbed by a concentration-independent mechanism without the involvement of the peptide carrier.
authors.affiliation: College of Pharmacy, University of Michigan, Ann Arbor 48109-1065.
authors.forename: D I
authors.initials: DI
authors.lastname: Friedman
authors.forename: G L
authors.initials: GL
authors.lastname: Amidon
mesh_terms: D000806:Angiotensin-Converting Enzyme Inhibitors / Q000493:pharmacokinetics*; D000818:Animals; D001692:Biological Transport; D002851:Chromatography, High Pressure Liquid; D004656:Enalapril / Q000493:pharmacokinetics*; D017328:Fosinopril; D006868:Hydrolysis; D007408:Intestinal Absorption / Q000502:physiology*; D007583:Jejunum / Q000378:metabolism; D010477:Perfusion; D010539:Permeability; D011355:Prodrugs / Q000493:pharmacokinetics*; D011392:Proline / Q000031:analogs & derivatives* / Q000493:pharmacokinetics; D051381:Rats; D012588:Scintillation Counting
chemical_list: D000806:Angiotensin-Converting Enzyme Inhibitors; D011355:Prodrugs; D004656:Enalapril; D011392:Proline; D017328:Fosinopril