Article Text

Download PDFPDF
Repetitive myocardial stunning in pigs is associated with an increased formation of reactive nitrogen species
  1. C S R Baker1,
  2. M T Frost3,
  3. O Rimoldi1,
  4. K Moore2,
  5. B Halliwell3,*,
  6. J M Polak1,
  7. P G Camici1,
  8. R J C Hall1
  1. 1Imperial College School of Medicine, Hammersmith Hospital, London, UK
  2. 2Royal Free & University College Medical School, London, UK
  3. 3International Antioxidant Research Centre, Guy's, King's and Thomas's School of Biomedical Sciences, London, UK
  1. Correspondence to:
    Dr Christopher SR Baker, Department of Cardiology, London Chest Hospital, Bonner Road, London E2 9JX, UK;
    csrbaker{at}blueyonder.co.uk

Statistics from Altmetric.com

Request Permissions

If you wish to reuse any or all of this article please use the link below which will take you to the Copyright Clearance Center’s RightsLink service. You will be able to get a quick price and instant permission to reuse the content in many different ways.

The “oxyradical hypothesis” of myocardial stunning proposes that superoxide, released on reperfusion, leads to contractile dysfunction via the production of the more reactive hydroxyl free radical from the iron catalysed Haber-Weiss reaction. However, superoxide reacts many times faster with nitric oxide (NO), than with ferric iron, leading to the formation of peroxynitrite (ONOO), which is a potent oxidising and nitrating agent with properties and reactivity similar to hydroxyl radicals. Consequently ONOO is a candidate for the initiation of oxidation reactions following brief ischaemia–reperfusion injury. The production of reactive nitrogen intermediates such as ONOO is reflected in vivo by the formation of the amino acid derivative 3-nitrotyrosine. Recently, we have developed a sensitive method for the quantitative analysis of tissue nitrotyrosine which avoids the artefactual formation of nitrotyrosine that can occur with more conventional protein preparative steps.1 The present study sought to test the hypothesis that myocardial stunning causes increased formation of tissue nitrotyrosine.

METHODS

Large White pigs (mean (SD) weight 38 (4) kg) were anaesthetised and prepared as previously described2 to allow temporary occlusion of the circumflex coronary artery with simultaneous recording of haemodynamic parameters, circumflex coronary blood flow (group A only) and regional and distal myocardial contractile function by sonomicrometric segment shortening. Following 30 minutes of stabilisation, regional ischaemia–reperfusion was induced by 10 cycles …

View Full Text

Footnotes

  • * Also the Department of Biochemistry, National University of Singapore

  • Sources of support: British Heart Foundation Junior Fellowship (FS/97006).