Cholesterol diet-induced hyperlipidemia impairs the cardioprotective effect of postconditioning: role of peroxynitrite
| Autor: | Péter Ferdinandy, De Wet Marais, Krisztina Kupai, Louise Odendaal, Tamás Csont, Csaba Csonka, Veronika Fekete, Jacques van Rooyen |
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| Rok vydání: | 2009 |
| Předmět: |
Male
Cholesterol diet Normal diet Physiology Metalloporphyrins Myocardial Infarction Hyperlipidemias Myocardial Reperfusion Injury Pharmacology Cholesterol Dietary chemistry.chemical_compound Stress Physiological Physiology (medical) Peroxynitrous Acid Hyperlipidemia medicine Animals Cardioprotection business.industry Cholesterol Myocardium medicine.disease Rats Disease Models Animal Biochemistry chemistry Coronary occlusion Circulatory system Tyrosine Cardiology and Cardiovascular Medicine business Peroxynitrite Biomarkers Signal Transduction |
| Zdroj: | American journal of physiology. Heart and circulatory physiology. 297(5) |
| ISSN: | 1522-1539 |
| Popis: | The aim of the present study was to investigate if hyperlipidemia interferes with the infarct size-limiting effect of postconditioning and to study the involvement of peroxynitrite in this phenomenon. Rats were fed a 2% cholesterol-enriched or normal diet for 12 wk. Infarct size by triphenyltetrazolium chloride staining was measured in hearts isolated from both groups and subjected to 30 min coronary occlusion followed by 120 min reperfusion with or without the postconditioning protocol induced by six cycles of 10 s coronary occlusion and 10 s reperfusion at the onset of the reperfusion. Postconditioning significantly decreased infarct size in the normolipidemic but not in the hyperlipidemic group. Postconditioning increased cardiac 3-nitrotyrosine concentration (a marker for peroxynitrite formation) in the normal but not in the cholesterol-fed group when measured at the 5th min of reperfusion. Next, we tested if the postconditioning-induced acute increase in peroxynitrite is involved in the cardioprotection in normolipidemic animals in separate experiments. Postconditioning failed to decrease infarct size in the presence of the peroxynitrite decomposition catalyst 5,10,15,20-tetrakis-[4-sulfonatophenyl]-porphyrinato-iron [III] (20 mg/l) in normolipidemic animals. We conclude that an early increase in peroxynitrite after postconditioning plays a role in cardioprotection. Furthermore, hyperlipidemia blocks the cardioprotective effect of postconditioning at least in part via deterioration of the postconditioning-induced early increase in peroxynitrite formation. |
| Databáze: | OpenAIRE |
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