Hyperbaric oxygenation pretreatment induces catalase and reduces infarct size in ischemic rat myocardium.
Ischemia-reperfusion injury is a major complication occurring in heart stroke, cardiopulmonary bypass surgeries, and heart transplantation. Reactive oxygen species generated during the reperfusion phase overwhelm the scavenging capacities of antioxidant enzymes, and result in oxidative damage to the myocardium. We examined whether hyperbaric oxygenation (HBO) pretreatment induces antioxidant enzymes and protects the heart from subsequent ischemia-reperfusion injury. Rats were intermittently exposed to 100% O2 at 3 ATA (where ATA is absolute atmosphere) for 1 h daily and then sacrificed after 24 h of recovery in room air. Isolated hearts were subjected to 40 min of ischemia and 90 min of reperfusion. HBO pretreatment was found to condition the heart and enhance enzymatic activity and gene expression of catalase, thereby significantly reducing infarct size after reperfusion. A catalase inhibitor, 3-amino-1,2,4-triazole, completely abolished the infarct-limiting effect of HBO pretreatment, which suggests that HBO-induced tolerance against ischemia-reperfusion injury is due to catalase induction. Our results imply that HBO preconditioning may be developed as a new preventive measure for reperfusion injury in the heart.
Kim
C H
CH
Department of Pharmacology and BK21 Human Life Sciences, Seoul National University College of Medicine and Heart Research Institute SNUMRC, South Korea. kimmsu@snu.ac.kr
Choi
H
H
Chun
Y S
YS
Kim
G T
GT
Park
J W
JW
Kim
M S
MS
D000640:Amitrole / Q000494:pharmacology; D000818:Animals; D002374:Catalase / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism*; D004791:Enzyme Inhibitors / Q000494:pharmacology; D015971:Gene Expression Regulation, Enzymologic; D006931:Hyperbaric Oxygenation; D008297:Male; D009203:Myocardial Infarction / Q000378:metabolism / Q000473:pathology / Q000628:therapy*; D015428:Myocardial Reperfusion Injury / Q000378:metabolism / Q000473:pathology / Q000628:therapy; D009206:Myocardium / Q000201:enzymology* / Q000473:pathology; D012333:RNA, Messenger / Q000032:analysis; D051381:Rats; D017207:Rats, Sprague-Dawley; D013047:Specific Pathogen-Free Organisms
D004791:Enzyme Inhibitors; D012333:RNA, Messenger; D002374:Catalase; D000640:Amitrole