Abstract | BACKGROUND AND PURPOSE:
Thioredoxin (Trx) is an oxidoreductase that prevents free radical-induced cell death in cultured cells. Here we assessed the mechanism(s) underlying the cardioprotective effects of Trx in vivo. EXPERIMENTAL APPROACH: KEY RESULTS: Treatment with 2 mg kg(-1) rhTrx significantly decreased myocardial apoptosis and reduced infarct size (P<0.01). Nitrotyrosine content of cardiomyocytes was markedly reduced in rhTrx-treated animals (P<0.01). To further identify the mechanisms by which rhTrx may exert its anti-nitrative effect, iNOS expression and production of NOx and superoxide were determined. Treatment with rhTrx had no significant effect on iNOS expression or NOx content in the ischemic/reperfused heart. However, it markedly upregulated mSOD and reduced tissue superoxide content. To further establish a causative link between the anti- peroxynitrite effect and the cardioprotective effect of rhTrx, cultured adult cardiomyocytes were incubated with SIN-1, a peroxynitrite donor, (50 microM for 3 h) resulting in a nitrotyrosine content comparable to that seen in the ischemic/reperfused heart and causing significant cardiomyocyte apoptosis (P<0.01). Treatment with rhTrx markedly decreased SIN-1 induced apoptosis (P<0.01). CONCLUSIONS AND IMPLICATIONS: These results demonstrate that Trx is a novel anti-apoptotic and cardioprotective molecule that exerts its cardioprotective effects by reducing ischemia/reperfusion-induced oxidative/nitrative stress.
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Authors | L Tao, E Gao, A Hu, C Coletti, Y Wang, T A Christopher, B L Lopez, W Koch, X L Ma |
Journal | British journal of pharmacology
(Br J Pharmacol)
Vol. 149
Issue 3
Pg. 311-8
(Oct 2006)
ISSN: 0007-1188 [Print] England |
PMID | 16921396
(Publication Type: Journal Article, Research Support, N.I.H., Extramural, Research Support, Non-U.S. Gov't)
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Chemical References |
- Superoxides
- Peroxynitrous Acid
- Nitric Oxide
- 3-nitrotyrosine
- Tyrosine
- Thioredoxins
- linsidomine
- Molsidomine
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Topics |
- Animals
- Apoptosis
(drug effects)
- Male
- Mice
- Molsidomine
(analogs & derivatives, pharmacology)
- Myocardial Ischemia
(drug therapy, pathology)
- Myocardium
(pathology)
- Myocytes, Cardiac
(drug effects, pathology)
- Nitric Oxide
(biosynthesis)
- Oxidative Stress
(drug effects)
- Peroxynitrous Acid
(metabolism)
- Superoxides
(metabolism)
- Thioredoxins
(pharmacology)
- Tyrosine
(analogs & derivatives, analysis)
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