Isoflurane late preconditioning against myocardial stunning is associated with enhanced antioxidant defenses.

Abstract

BACKGROUND:

We tested the hypothesis that an upregulation of antioxidant proteins [Cu-Zn superoxide dismutase (SOD), Mn SOD, catalase, glutathione peroxidase, and glutathione peroxidase] plays a role in the delayed protection against myocardial stunning produced by isoflurane preconditioning (ISOPC). Findings were compared with late ischemic PC (IPC).

METHODS:

Fourteen mongrel dogs were chronically instrumented to measure coronary blood flow and myocardial wall thickening (WT) in conscious state. In Group 1, dogs underwent IPC, induced by a 10-min coronary artery occlusion (CAO); after 24 h of reperfusion, they were subjected to a second 10-min ischemia CAO-reperfusion. In Group 2 (ISOPC), dogs inhaled one minimum alveolar concentration (MAC) ISO (1.4% in O(2)) for 60 min, allowed to recover for 24 h, and then subjected to CAO ischemia-reperfusion. Recovery of WT following the initial 10-min CAO in Group 1 served as control response for both ISOPC and IPC. Expression and activity of antioxidant proteins were measured using Western blotting and spectrophotometric techniques, respectively.

RESULTS:

Two to three hours of reperfusion were required for recovery of WT following either ISOPC or IPC; in contrast, without PC, WT remained markedly reduced (30% below baseline) at this time point and required more than 6 h of reperfusion for recovery. Neither IPC nor ISOPC affected expression of Cu-Zn SOD, Mn SOD, or catalase. However, ISOPC increased activity of Mn SOD (+40%), catalase (+39%), glutathione peroxidase (+37%), and glutathione reductase (+93%) (P < 0.05); IPC had similar effects.

CONCLUSION:

ISOPC had powerful, delayed anti-stunning effect that was associated with an enhancement of endogenous antioxidant defenses.

• Authors: G J Crystal, G Malik, S-H Yoon, S-J Kim
• Journal: Acta anaesthesiologica Scandinavica (Acta Anaesthesiol Scand) Vol. 56 Issue 1 Pg. 39-47 (Jan 2012) ISSN: 1399-6576 [Electronic] England
• PMID: 22103751 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't)
• Copyright: © 2011 The Authors Acta Anaesthesiologica Scandinavica © 2011 The Acta Anaesthesiologica Scandinavica Foundation.

Chemical References

• Anesthetics, Inhalation
• Antioxidants
• Reactive Oxygen Species
• Superoxides
• Hydroxyl Radical
• Hydrogen Peroxide
• Isoflurane
• Catalase
• Glutathione Peroxidase
• Superoxide Dismutase
• Glutathione Reductase

Topics

• Anesthetics, Inhalation (pharmacology)
• Animals
• Antioxidants (metabolism)
• Blood Pressure (drug effects)
• Blotting, Western
• Catalase (metabolism)
• Coronary Circulation
• Dogs
• Female
• Glutathione Peroxidase (metabolism)
• Glutathione Reductase (metabolism)
• Heart Rate (drug effects)
• Hydrogen Peroxide (metabolism)
• Hydroxyl Radical (metabolism)
• Ischemic Preconditioning, Myocardial (methods)
• Isoflurane (pharmacology)
• Male
• Myocardial Stunning (prevention & control)
• Oxygen Consumption (drug effects)
• Reactive Oxygen Species (metabolism)
• Superoxide Dismutase (metabolism)
• Superoxides (metabolism)