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Oxidation‐reduction state modifies vascular reactivity
Author(s) -
Choi Hyehun,
Webb R. Clinton,
Lamb Fred S
Publication year - 2012
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.26.1_supplement.863.7
Subject(s) - chemistry , redox , cystine , cysteine , sodium nitroprusside , glutathione , phenylephrine , thiol , acetylcholine , biophysics , endocrinology , biochemistry , nitric oxide , inorganic chemistry , enzyme , organic chemistry , blood pressure , biology , medicine
Oxidation‐reduction (redox) reactions of cell surface thiol/disulfide couples regulate cellular processes and Cysteine/Cystine (Cys/CySS) is the predominant extracellular low‐molecular‐weight thiol/disulfide couple. We hypothesized that redox state regulates vascular reactivity independent of reactive oxygen species. Aortic rings from C57BL/6 mice were treated with varying concentrations of Cys/CySS, and vascular contraction and relaxation assessed. Acute exposure (40 min) to a reduced (−150 mV) state decreased relaxation to acetylcholine (Ach), not contraction to phenylephrine (PE), and an oxidized (0 mV) state had no effect on either Ach or PE compared to a neutral (−80 mV) state. After 4 hours, relaxation to Ach was impaired in the reduced, but enhanced in the oxidized state (control E max = 88 ± 1.9 %, reduced E max = 67 ± 2.3 %; control pD 2 = 7.3 ± 0.07, oxidized pD 2 = 7.7 ± 0.07, * p <0.05, n=10 to 12). Relaxation to sodium nitroprusside was unaltered. Contraction to PE was enhanced by reduced and attenuated by oxidized conditions (control E max = 110 ± 3.4 %, reduced E max = 143 ± 4.1 %, oxidized E max = 94 ± 3.8 %, * p <0.05, n=10 to 12). Contractions to KCl and serotonin were unaffected. Thus redox state specifically modifies vascular reactivity in a receptor‐dependent fashion. It remains to be determined if these effects are physiologically significant in disease states associated with altered serum redox states.