title: [Mitochondrial calcium uniporter participates in TNF-alpha induced cardioprotection in isolated rat hearts subjected to ischemia/reperfusion].
abstract: OBJECTIVE
  To investigate whether mitochondrial calcium uniporter participates in the cardioprotection of tumor necrosis factor alpha (TNFalpha) pretreatment in isolated rat hearts subjected to ischemia/reperfusion.
  
  
  METHODS
  Isolated perfused rat hearts were subjected to 30 min regional ischemia (occlusion of left anterior descending artery) and 120 min reperfusion. The infarct size, coronary flow (CF) and lactate dehydrogenase (LDH) release during reperfusion were measured. The mitochondria of the heart were isolated and suspended in the swelling buffer for measurement of absorbance at 520 nm.
  
  
  RESULTS
  Pretreatment with TNFa at 10 U/ml for 7 min followed by 10 min washout reduced the infarct size and LDH release, and improved the recovery of CF during reperfusion. Administration of spermine (20 micromol/L), an opener of mitochondrial calcium uniporter, for 10 min during early reperfusion attenuated the reduction of infarct size and LDH release, and improvement of CF induced by TNFalpha. In isolated mitochondria of the heart pretreated with TNFalpha, the absorbance at 520 nm decreased less than that of mitochondria without TNFalpha pretreatment. Administration of spermine (50 micromol/L) attenuated the change of the absorbance induced by TNFalpha.
  
  
  CONCLUSIONS
  The findings indicate that TNFalpha protects myocardium against ischemia/reperfusion injury via inhibiting mitochondrial calcium uniporter opening as well as mitochondrial permeability transition pore opening.
authors.affiliation: Department of Physiology, Zhejiang University School of Medicine, Hangzhou 310031, China.
authors.forename: Qin
authors.initials: Q
authors.lastname: Gao
authors.forename: Shi-zhong
authors.initials: SZ
authors.lastname: Zhang
authors.forename: Huan-hao
authors.initials: HH
authors.lastname: Mao
authors.forename: Qing-song
authors.initials: QS
authors.lastname: Li
authors.forename: Chun-mei
authors.initials: CM
authors.lastname: Cao
authors.forename: Qiang
authors.initials: Q
authors.lastname: Xia
mesh_terms: D000818:Animals; D015220:Calcium Channels / Q000187:drug effects / Q000378:metabolism*; D002316:Cardiotonic Agents / Q000494:pharmacology*; D066298:In Vitro Techniques; D019157:Ischemic Preconditioning, Myocardial / Q000379:methods; D008297:Male; D033681:Mitochondrial Membrane Transport Proteins / Q000187:drug effects*; D000083162:Mitochondrial Permeability Transition Pore; D015428:Myocardial Reperfusion Injury / Q000517:prevention & control; D051381:Rats; D017207:Rats, Sprague-Dawley; D013096:Spermine / Q000494:pharmacology; D014409:Tumor Necrosis Factor-alpha / Q000494:pharmacology*
chemical_list: D015220:Calcium Channels; D002316:Cardiotonic Agents; D033681:Mitochondrial Membrane Transport Proteins; D000083162:Mitochondrial Permeability Transition Pore; D014409:Tumor Necrosis Factor-alpha; C034703:mitochondrial calcium uniporter; D013096:Spermine