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Acute Hyperglycemia Abolishes Ischemic Preconditioning by Inhibiting Akt Phosphorylation : Normalizing Blood Glucose before Ischemia Restores Ischemic Preconditioning
Joint Authors
Hennessy, Sara
Tian, Yikui
Kron, Irving L.
Yang, Zequan
French, Brent A.
Liu, Yuan
Source
Oxidative Medicine and Cellular Longevity
Issue
Vol. 2013, Issue 2013 (31 Dec. 2013), pp.1-8, 8 p.
Publisher
Hindawi Publishing Corporation
Publication Date
2013-11-25
Country of Publication
Egypt
No. of Pages
8
Main Subjects
Natural & Life Sciences (Multidisciplinary)
Biology
Abstract EN
This study examined the hypothesis that acute hyperglycemia (HG) blocks ischemic preconditioning (IPC) by inhibiting Akt phosphorylation.
Brief HG of approximately 400 mg/dL was induced in C57BL/6 mice via intraperitoneal injection of 20% dextrose (2 g/kg).
All mice underwent 40 min LAD occlusion and 60 min reperfusion.
The IPC protocol was 2 cycles of 5 min ischemia and 5 min reperfusion prior to index ischemia.
Results.
In control mice, infarct size (IF) was 51.7 ± 2.0 (% risk region).
Preconditioning reduced IF by 50% to 25.8 ± 3.2 (P<0.05 versus control).
In HG mice, IF was significantly exacerbated to 58.1 ± 2.3.
However, the effect of IPC completely disappeared in HG mice.
Normalization of blood glucose with insulin 5 min before IPC recovered the cardioprotective effect.
Administration of CCPA before index ischemia mimicked IPC effect.
The cardioprotective effect of CCPA, not its chronotropic effect, completely disappeared in HG mice.
Phosphorylation of cardiac tissue Akt before index ischemia was enhanced by IPC or CCPA but was significantly inhibited by HG in both groups.
Normalization of glucose with insulin reversed the inhibition of Akt phosphorylation by HG.
Conclusion.
HG abolishes the cardioprotective effect of preconditioning by inhibiting Akt phosphorylation.
Normalization of blood glucose with insulin suffices to recover the cardioprotective effect of preconditioning.
American Psychological Association (APA)
Yang, Zequan& Tian, Yikui& Liu, Yuan& Hennessy, Sara& Kron, Irving L.& French, Brent A.. 2013. Acute Hyperglycemia Abolishes Ischemic Preconditioning by Inhibiting Akt Phosphorylation : Normalizing Blood Glucose before Ischemia Restores Ischemic Preconditioning. Oxidative Medicine and Cellular Longevity،Vol. 2013, no. 2013, pp.1-8.
https://search.emarefa.net/detail/BIM-463991
Modern Language Association (MLA)
Yang, Zequan…[et al.]. Acute Hyperglycemia Abolishes Ischemic Preconditioning by Inhibiting Akt Phosphorylation : Normalizing Blood Glucose before Ischemia Restores Ischemic Preconditioning. Oxidative Medicine and Cellular Longevity No. 2013 (2013), pp.1-8.
https://search.emarefa.net/detail/BIM-463991
American Medical Association (AMA)
Yang, Zequan& Tian, Yikui& Liu, Yuan& Hennessy, Sara& Kron, Irving L.& French, Brent A.. Acute Hyperglycemia Abolishes Ischemic Preconditioning by Inhibiting Akt Phosphorylation : Normalizing Blood Glucose before Ischemia Restores Ischemic Preconditioning. Oxidative Medicine and Cellular Longevity. 2013. Vol. 2013, no. 2013, pp.1-8.
https://search.emarefa.net/detail/BIM-463991
Data Type
Journal Articles
Language
English
Notes
Includes bibliographical references
Record ID
BIM-463991