Role of tumor necrosis factor alpha and its receptor I in preconditioning by hyperoxia.
Hyperoxic pretreatment (>95% O(2)) can evoke myocardial adaptation to ischemia, a method which is potentially clinically usable. We wanted to investigate the role of tumor necrosis factor alpha (TNFalpha) and its p55 receptor (receptor I) in signaling of hyperoxic adaptation to ischemia. Mice deficient for TNFalpha (TNFalpha -/-) or the TNF receptor I (TNFRI -/-) gene and their wild types were subjected to 60 minutes of hyperoxia or sham treatment. Their lungs were then collected for immunoblotting, their hearts isolated and subjected to global ischemia and reperfusion in a Langendorff system, and aortic rings mounted in organ baths for reactivity studies. Hyperoxia increased expression of TNFalpha and TNFalpha converting enzyme in pulmonary proteins from wild type mice, in which hyperoxia increased myocardial tolerance to ischemia. Post-ischemic heart function was improved and infarct size reduced in wild type mice, but not in TNFalpha -/- or TNFRI -/-. The contractile response to TNFalpha on aortic rings was attenuated by hyperoxic pretreatment and by TNFRI -/-. Thus we conclude that TNFalpha, acting through TNFRI, appears important for the protective effects of hyperoxia.
Labruto
Fausto
F
Crafoord Laboratory, L6:00, Karolinska Hospital, 17176 Stockholm, Sweden. lampo18@yahoo.com
Yang
Jiangning
J
Vaage
Jarle
J
Valen
Guro
G
D051722:ADAM Proteins / Q000378:metabolism; D000072198:ADAM17 Protein; D000109:Acetylcholine / Q000494:pharmacology; D000818:Animals; D001011:Aorta / Q000187:drug effects / Q000502:physiology; D015237:Dinoprost / Q000494:pharmacology; D004797:Enzyme-Linked Immunosorbent Assay; D018496:Hyperoxia / Q000378:metabolism*; D019157:Ischemic Preconditioning, Myocardial; D051379:Mice; D008810:Mice, Inbred C57BL; D018345:Mice, Knockout; D009203:Myocardial Infarction / Q000378:metabolism / Q000473:pathology / Q000503:physiopathology; D017202:Myocardial Ischemia / Q000378:metabolism* / Q000473:pathology / Q000503:physiopathology; D009599:Nitroprusside / Q000494:pharmacology; D010656:Phenylephrine / Q000494:pharmacology; D047888:Receptors, Tumor Necrosis Factor, Type I / Q000235:genetics / Q000378:metabolism*; D014409:Tumor Necrosis Factor-alpha / Q000235:genetics / Q000378:metabolism*; D014662:Vasoconstrictor Agents / Q000494:pharmacology; D014665:Vasodilator Agents / Q000494:pharmacology; D017725:Ventricular Pressure
D047888:Receptors, Tumor Necrosis Factor, Type I; D014409:Tumor Necrosis Factor-alpha; D014662:Vasoconstrictor Agents; D014665:Vasodilator Agents; D009599:Nitroprusside; D010656:Phenylephrine; D015237:Dinoprost; D051722:ADAM Proteins; D000072198:ADAM17 Protein; D000109:Acetylcholine