title: Free radicals-induced changes in mesenteric microvascular dimensions in the anesthetized cat.
abstract: Effect of free radicals on microvascular dimensions was studied in anesthetized cat intestinal mesentery. Generation of free radicals by xanthine oxidase, acting on endogenous substrates (e.g., xanthine, hypoxanthine), produced sustained vasodilation at pH 7.4 or at pH 6.6. These effects were reversed by superoxide dismutase (SOD), a superoxide radical (.O2-) scavenger, at pH 7.4, and by SOD plus hydroxyl radical (.OH) scavenger d-mannitol at pH 6.6. These findings suggest that the sustained vasodilation is caused by .O2- and by .OH derived from .O2- at low pH.
mesh_terms: D000758:Anesthesia; D000818:Animals; D002415:Cats; D005260:Female; D005609:Free Radicals; D006863:Hydrogen-Ion Concentration; D006878:Hydroxides; D017665:Hydroxyl Radical; D008054:Lipid Peroxides / Q000378:metabolism; D008297:Male; D008643:Mesentery / Q000098:blood supply; D008833:Microcirculation / Q000187:drug effects* / Q000473:pathology; D013482:Superoxide Dismutase / Q000494:pharmacology; D013481:Superoxides / Q000633:toxicity*; D014969:Xanthine Oxidase / Q000494:pharmacology
chemical_list: D005609:Free Radicals; D006878:Hydroxides; D008054:Lipid Peroxides; D013481:Superoxides; D017665:Hydroxyl Radical; D013482:Superoxide Dismutase; D014969:Xanthine Oxidase