Details

Autor(en) / Beteiligte

• Clark, James E
• Foresti, Roberta
• Sarathchandra, Padmini
• Kaur, Harparkash
• Green, Colin J
• Motterlini, Roberto

Titel

Heme oxygenase-1-derived bilirubin ameliorates postischemic myocardial dysfunction

Ist Teil von

• American journal of physiology. Heart and circulatory physiology, 2000-02, Vol.278 (2), p.H643-H651

Ort / Verlag

United States

Erscheinungsjahr

2000

Quelle

MEDLINE

Beschreibungen/Notizen

• 1  Restoration of Appearance and Function Trust, Institute of Plastic Surgery, Mount Vernon Hospital, Northwood HA6 2RN; 2  Vascular Biology Unit, Department of Surgical Research, Northwick Park Institute for Medical Research, Harrow HA1 3UJ, United Kingdom Bilirubin is a potent antioxidant generated intracellularly during the degradation of heme by the enzyme heme oxygenase. The purpose of this study was to determine the role of increased cardiac bilirubin in protection against postischemic myocardial dysfunction. Rat hearts were isolated and perfused according to the Langendorff technique to evaluate the recovery of myocardial function after 30 min of global ischemia and 60 min of reperfusion. We found that upregulation of the inducible isoform of heme oxygenase (HO-1) by treatment of animals with hemin 24 h before ischemia ameliorated myocardial function and reduced infarct size (tetrazolium staining) on reperfusion of isolated hearts. Tin protoporphyrin IX, an inhibitor of heme oxygenase activity, completely abolished the improved postischemic myocardial performance observed after hemin-mediated HO-1 induction. Likewise, cardiac tissue injury was exacerbated by treatment with tin protoporphyrin IX. Increased cardiac HO-1 expression and heme oxygenase activity were associated with enhanced tissue bilirubin content and an increased rate of bilirubin release into the perfusion buffer. Furthermore, exogenously administered bilirubin at concentrations as low as 100 nanomolar significantly restored myocardial function and minimized both infarct size and mitochondrial damage on reperfusion. Our data provide strong evidence for a primary role of HO-1-derived bilirubin in cardioprotection against reperfusion injury. antioxidant genes; heat shock proteins; preconditioning; infarct size; carbon monoxide