title: Phytic acid suppresses ischemia-induced hydroxyl radical generation in rat myocardium.
abstract: The present study examined whether ischemia-reperfusion-induced hydroxyl radical (·OH) generation was attenuated by myo-inositol hexaphosphoric acid (phytic acid). A flexibly mounted microdialysis technique was used to detect the generation of ·OH in in vivo rat hearts. To measure the level of ·OH, sodium salicylate in Ringer's solution (0.5mM or 0.5 nmol/μl/min) was infused directly through a microdialysis probe to detect the generation of ·OH as reflected by the nonenzymatic formation of 2,3-dihydroxybenzoic acid (2,3-DHBA). To confirm the generation of ·OH by Fenton-type reaction, iron(II) was infused through a microdialysis probe. A positive linear correlation between iron(II) and the formation of 2,3-DHBA (R(2)=0.983) was observed. However, the level of 2,3-DHBA in norepinephrine (100 μM) plus phytic acid (100 μM) treated group were significantly lower than those observed in norepinephrine-only-treated group (n=6, *p<0.05). To examine the effect of phytic acid on ischemia-reperfusion-induced ·OH generation, the heart was subjected to myocardial ischemia for 15 min by occlusion of the left anterior descending coronary artery (LAD). When the heart was reperfused, the normal elevation of 2,3-DHBA in the heart dialysate was not observed in animals pretreated with phytic acid. These results suggest that phytic acid is associated with antioxidant effect due to the suppression of iron-induced ·OH generation.
authors.affiliation: School of Nursing, Faculty of Health Sciences, Osaka Aoyama University, 2-11-1 Niina, Mino City, Japan. Electronic address: t-obata@osaka-aoyama.ac.jp.
authors.forename: Toshio
authors.initials: T
authors.lastname: Obata
authors.affiliation: Department of Nursing, School of Health Sciences, Asahi University, 1851 Hozumi, Mizuho City, Gifu, Japan.
authors.forename: Michiko
authors.initials: M
authors.lastname: Nakashima
mesh_terms: D000818:Animals; D000975:Antioxidants / Q000494:pharmacology*; D004305:Dose-Response Relationship, Drug; D006321:Heart / Q000187:drug effects*; D017665:Hydroxyl Radical / Q000378:metabolism*; D008297:Male; D017202:Myocardial Ischemia / Q000378:metabolism*; D009206:Myocardium / Q000378:metabolism*; D010833:Phytic Acid / Q000494:pharmacology*; D051381:Rats; D017208:Rats, Wistar; D020156:Salicylic Acid / Q000494:pharmacology
chemical_list: D000975:Antioxidants; D017665:Hydroxyl Radical; D010833:Phytic Acid; D020156:Salicylic Acid
keywords: Hydroxyl radical; Iron(II); Ischemia; Microdialysis; Norepinephrine; Phytic acid