title: Nitric oxide donor-induced hyperpermeability of cultured intestinal epithelial monolayers: role of superoxide radical, hydroxyl radical, and peroxynitrite.
abstract: Many of the cytopathic effects of nitric oxide (NO*) are mediated by peroxynitrite (PN), a product of the reaction between NO* and superoxide radical (O2*-). In the present study, we investigated the role of PN, O2*- and hydroxyl radical (OH*) as mediators of epithelial hyperpermeability induced by the NO* donor, S-nitroso-N-acetylpenicillamine (SNAP), and the PN generator, 3-morpholinosydnonimine (SIN-1). Caco-2BBe enterocytic monolayers were grown on permeable supports in bicameral chambers. Epithelial permeability, measured as the apical-to-basolateral flux of fluorescein disulfonic acid, increased after 24 h of incubation with 5.0 mM SNAP or SIN-1. Addition of 2-(4-carboxyphenyl)-4,4,5,5-tetramethylimidazoline-1-oxyl-3-oxide, an NO* scavenger, or Tiron, an O2*- scavenger, reduced the increase in permeability induced by both donor compounds. The SNAP-induced increase in permeability was prevented by allopurinol, an inhibitor of xanthine oxidase (a source of endogenous O2*-). Diethyldithiocarbamate, a superoxide dismutase inhibitor, and pyrogallol, an O2* generator, potentiated the increase in permeability induced by SNAP. Addition of the PN scavengers deferoxamine, urate, or glutathione, or the OH* scavenger mannitol, attenuated the increase in permeability induced by both SNAP and SIN-1. Both donor compounds decreased intracellular levels of glutathione and protein-bound sulfhydryl groups, suggesting the generation of a potent oxidant. These results support a role for PN, and possibly OH*, in the pathogenesis of NO* donor-induced intestinal epithelial hyperpermeability.
authors.affiliation: Department of Surgery, Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, MA 02215, USA. mmenconi@bidmc.harvard.edu
authors.forename: M J
authors.initials: MJ
authors.lastname: Menconi
authors.forename: N
authors.initials: N
authors.lastname: Unno
authors.forename: M
authors.initials: M
authors.lastname: Smith
authors.forename: D E
authors.initials: DE
authors.lastname: Aguirre
authors.forename: M P
authors.initials: MP
authors.lastname: Fink
mesh_terms: D000975:Antioxidants / Q000494:pharmacology; D018938:Caco-2 Cells; D004847:Epithelial Cells / Q000187:drug effects / Q000502:physiology; D016166:Free Radical Scavengers / Q000494:pharmacology; D005978:Glutathione / Q000378:metabolism; D006801:Humans; D017665:Hydroxyl Radical / Q000494:pharmacology; D007408:Intestinal Absorption / Q000187:drug effects* / Q000502:physiology; D007422:Intestines / Q000187:drug effects / Q000502:physiology; D007700:Kinetics; D008981:Molsidomine / Q000031:analogs & derivatives / Q000494:pharmacology; D009566:Nitrates / Q000494:pharmacology; D009569:Nitric Oxide / Q000502:physiology; D020030:Nitric Oxide Donors / Q000494:pharmacology*; D010396:Penicillamine / Q000031:analogs & derivatives / Q000494:pharmacology; D010539:Permeability / Q000187:drug effects; D013482:Superoxide Dismutase / Q000494:pharmacology; D013481:Superoxides / Q000494:pharmacology
chemical_list: D000975:Antioxidants; D016166:Free Radical Scavengers; D009566:Nitrates; D020030:Nitric Oxide Donors; C110881:S-nitro-N-acetylpenicillamine; D013481:Superoxides; C039642:peroxynitric acid; D009569:Nitric Oxide; D017665:Hydroxyl Radical; C002385:linsidomine; D008981:Molsidomine; D013482:Superoxide Dismutase; D005978:Glutathione; D010396:Penicillamine