کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
10574100 976501 2005 10 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Assessments of the chemistry and vasodilatory activity of nitrite with hemoglobin under physiologically relevant conditions
موضوعات مرتبط
مهندسی و علوم پایه شیمی شیمی معدنی
پیش نمایش صفحه اول مقاله
Assessments of the chemistry and vasodilatory activity of nitrite with hemoglobin under physiologically relevant conditions
چکیده انگلیسی
Hypoxic vasodilation involves detection of the oxygen content of blood by a sensor, which rapidly transduces this signal into vasodilatory bioactivity. Current perspectives on the molecular mechanism of this function hold that hemoglobin (Hb) operates as both oxygen sensor and a condition-responsive NO reactor that regulates the dispensing of bioactivity through release of the NO group from the β-cys93 S-nitroso derivative of Hb, SNO-Hb. A common path to the formation of SNO-Hb involves oxidative transfer of the NO-group from heme to thiol. We have previously reported that the reaction of nitrite with deoxy-Hb, which furnishes heme-Fe(II)NO, represents one attractive route for the formation of SNO-Hb. Recent literature, however, posits that the nitrite-reductase reaction of Hb might produce physiological vasodilatory effects through NO that evades trapping on heme-Fe(II) and may be stored before release as Fe(III)NO. In this article, we briefly review current perspectives in NO biology on the nitrite-reductase reaction of Hb. We report in vitro spectroscopic (UV/Vis, EPR) studies that are difficult to reconcile with suggestions that this reaction either generates a heme-Fe(III)NO reservoir or significantly liberates NO. We further show in bioassay experiments that combinations of nitrite and deoxy-Hb - under conditions that suppress SNO-Hb formation - exhibit no direct vasodilatory activity. These results help underscore the differences between physiological, RBC-regulated, hypoxic vasodilation versus pharmacological effects of exogenous nitrite.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Journal of Inorganic Biochemistry - Volume 99, Issue 4, April 2005, Pages 912-921
نویسندگان
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