Late ischemic preconditioning is mediated in myocytes by enhanced endogenous antioxidant activity stimulated by oxygen-derived free radicals

Xiaolin Zhai, Xiaobo Zhou, Muhammad Ashraf

Research output: Contribution to journalArticle

20 Citations (Scopus)

Abstract

The primary objective of the study was to test the hypothesis that oxygen radical during initial anoxia stimulate endogenous antioxidant activity in late preconditioning in myocytes. Isolated rat myocytes were preconditioned in one group with two cycles of 5 minutes of anoxia and 5 minutes of reoxygenation and in another group with exogenous superoxide anion (·O2-) generated by reaction of xanthine oxidase with xanthine. Myocytes were kept for 24 hours, after which they were exposed to 60 minutes of anoxia and 60 minutes of reoxygenation. Preconditioned myocytes exhibited decreased LDH release, reduced malondialdehyde formation, increased cell viability, and well-preserved cell structure. ·O2- production was increased in myocytes immediately after treatment with repetitive anoxia (1.65 ± 0.08 nmol/mg protein) or exogenous ·O2- (1.42 ± 0.11 nmol/mg protein). Allopurinol, a xanthine oxidase inhibitor, abolished ·O2- production during the initial preconditioning period. Twenty-four hours later, Mn SOD activity declined in anoxic control myocytes (0.38 ± 0.06 U/mg protein), whereas it increased significantly in myocytes preconditioned with repetitive anoxia (3.25 ± 0.15 nmol/mg protein) or with exogenous ·O2- (2.27 ± 0.10 nmol/mg protein). The increase in Mn SOD activity and myocardial protective effects observed in preconditioned myocytes were totally blocked by allopurinol. These results indicate that oxygen radicals generated during the initial preconditioning period activate endogenous antioxidant defense (increased Mn SOD activity) 24 hours later, which contributes to the late cardioprotection of preconditioning.

Original languageEnglish (US)
Pages (from-to)156-166
Number of pages11
JournalAnnals of the New York Academy of Sciences
Volume793
DOIs
StatePublished - Jan 1 1996

Fingerprint

Ischemic Preconditioning
Muscle Cells
Free Radicals
Antioxidants
Oxygen
Superoxide Dismutase
Allopurinol
Xanthine Oxidase
Proteins
Reactive Oxygen Species
Xanthine
Malondialdehyde
Superoxides
Rats
Cells
Protein
Cell Survival
Hypoxia

ASJC Scopus subject areas

  • Neuroscience(all)
  • Biochemistry, Genetics and Molecular Biology(all)
  • History and Philosophy of Science

Cite this

@article{ef8033b75a1e48fc90dfa8c9edfd0898,
title = "Late ischemic preconditioning is mediated in myocytes by enhanced endogenous antioxidant activity stimulated by oxygen-derived free radicals",
abstract = "The primary objective of the study was to test the hypothesis that oxygen radical during initial anoxia stimulate endogenous antioxidant activity in late preconditioning in myocytes. Isolated rat myocytes were preconditioned in one group with two cycles of 5 minutes of anoxia and 5 minutes of reoxygenation and in another group with exogenous superoxide anion (·O2-) generated by reaction of xanthine oxidase with xanthine. Myocytes were kept for 24 hours, after which they were exposed to 60 minutes of anoxia and 60 minutes of reoxygenation. Preconditioned myocytes exhibited decreased LDH release, reduced malondialdehyde formation, increased cell viability, and well-preserved cell structure. ·O2- production was increased in myocytes immediately after treatment with repetitive anoxia (1.65 ± 0.08 nmol/mg protein) or exogenous ·O2- (1.42 ± 0.11 nmol/mg protein). Allopurinol, a xanthine oxidase inhibitor, abolished ·O2- production during the initial preconditioning period. Twenty-four hours later, Mn SOD activity declined in anoxic control myocytes (0.38 ± 0.06 U/mg protein), whereas it increased significantly in myocytes preconditioned with repetitive anoxia (3.25 ± 0.15 nmol/mg protein) or with exogenous ·O2- (2.27 ± 0.10 nmol/mg protein). The increase in Mn SOD activity and myocardial protective effects observed in preconditioned myocytes were totally blocked by allopurinol. These results indicate that oxygen radicals generated during the initial preconditioning period activate endogenous antioxidant defense (increased Mn SOD activity) 24 hours later, which contributes to the late cardioprotection of preconditioning.",
author = "Xiaolin Zhai and Xiaobo Zhou and Muhammad Ashraf",
year = "1996",
month = "1",
day = "1",
doi = "10.1111/j.1749-6632.1996.tb33512.x",
language = "English (US)",
volume = "793",
pages = "156--166",
journal = "Annals of the New York Academy of Sciences",
issn = "0077-8923",
publisher = "Wiley-Blackwell",

}

TY - JOUR

T1 - Late ischemic preconditioning is mediated in myocytes by enhanced endogenous antioxidant activity stimulated by oxygen-derived free radicals

AU - Zhai, Xiaolin

AU - Zhou, Xiaobo

AU - Ashraf, Muhammad

PY - 1996/1/1

Y1 - 1996/1/1

N2 - The primary objective of the study was to test the hypothesis that oxygen radical during initial anoxia stimulate endogenous antioxidant activity in late preconditioning in myocytes. Isolated rat myocytes were preconditioned in one group with two cycles of 5 minutes of anoxia and 5 minutes of reoxygenation and in another group with exogenous superoxide anion (·O2-) generated by reaction of xanthine oxidase with xanthine. Myocytes were kept for 24 hours, after which they were exposed to 60 minutes of anoxia and 60 minutes of reoxygenation. Preconditioned myocytes exhibited decreased LDH release, reduced malondialdehyde formation, increased cell viability, and well-preserved cell structure. ·O2- production was increased in myocytes immediately after treatment with repetitive anoxia (1.65 ± 0.08 nmol/mg protein) or exogenous ·O2- (1.42 ± 0.11 nmol/mg protein). Allopurinol, a xanthine oxidase inhibitor, abolished ·O2- production during the initial preconditioning period. Twenty-four hours later, Mn SOD activity declined in anoxic control myocytes (0.38 ± 0.06 U/mg protein), whereas it increased significantly in myocytes preconditioned with repetitive anoxia (3.25 ± 0.15 nmol/mg protein) or with exogenous ·O2- (2.27 ± 0.10 nmol/mg protein). The increase in Mn SOD activity and myocardial protective effects observed in preconditioned myocytes were totally blocked by allopurinol. These results indicate that oxygen radicals generated during the initial preconditioning period activate endogenous antioxidant defense (increased Mn SOD activity) 24 hours later, which contributes to the late cardioprotection of preconditioning.

AB - The primary objective of the study was to test the hypothesis that oxygen radical during initial anoxia stimulate endogenous antioxidant activity in late preconditioning in myocytes. Isolated rat myocytes were preconditioned in one group with two cycles of 5 minutes of anoxia and 5 minutes of reoxygenation and in another group with exogenous superoxide anion (·O2-) generated by reaction of xanthine oxidase with xanthine. Myocytes were kept for 24 hours, after which they were exposed to 60 minutes of anoxia and 60 minutes of reoxygenation. Preconditioned myocytes exhibited decreased LDH release, reduced malondialdehyde formation, increased cell viability, and well-preserved cell structure. ·O2- production was increased in myocytes immediately after treatment with repetitive anoxia (1.65 ± 0.08 nmol/mg protein) or exogenous ·O2- (1.42 ± 0.11 nmol/mg protein). Allopurinol, a xanthine oxidase inhibitor, abolished ·O2- production during the initial preconditioning period. Twenty-four hours later, Mn SOD activity declined in anoxic control myocytes (0.38 ± 0.06 U/mg protein), whereas it increased significantly in myocytes preconditioned with repetitive anoxia (3.25 ± 0.15 nmol/mg protein) or with exogenous ·O2- (2.27 ± 0.10 nmol/mg protein). The increase in Mn SOD activity and myocardial protective effects observed in preconditioned myocytes were totally blocked by allopurinol. These results indicate that oxygen radicals generated during the initial preconditioning period activate endogenous antioxidant defense (increased Mn SOD activity) 24 hours later, which contributes to the late cardioprotection of preconditioning.

UR - http://www.scopus.com/inward/record.url?scp=0029804387&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=0029804387&partnerID=8YFLogxK

U2 - 10.1111/j.1749-6632.1996.tb33512.x

DO - 10.1111/j.1749-6632.1996.tb33512.x

M3 - Article

C2 - 8906163

AN - SCOPUS:0029804387

VL - 793

SP - 156

EP - 166

JO - Annals of the New York Academy of Sciences

JF - Annals of the New York Academy of Sciences

SN - 0077-8923

ER -