Olivier W V van den Brink1, Andrew D Cochrane, Franklin L Rosenfeldt, Daniel J Penny, Salvatore Pepe. 1. Department of Cardiothoracic Surgery, Alfred Hospital, Department of Surgery, Monash University, Murdoch Children's Research Institute, Critical Care and Neurosciences, Heart Research, Victorian Paediatric Cardiac Surgery Unit, Department of Cardiology, Royal Children's Hospital and Department of Paediatrics, University of Melbourne, Melbourne, Victoria, Australia.
Abstract
BACKGROUND: Cardiac opioid peptides have been identified to exert important adaptive metabolic signalling for cardioprotection against ischaemia or hypoxia-related injury. AIMS: To determine myocardial methionine-enkephalin content in children with hypoxemic congenital heart defects and to correlate myocardial content of methionine-enkephalin with the extent of arterial oxygen desaturation. METHODS: Children (n= 20, median age of 16 months), undergoing cardiac surgical repair (tetralogy of Fallot, 17/20), were included in this study. Arterial oxygen saturation was measured on admission. Myocardial samples obtained during surgery were assayed via radioimmunochemistry for methionine-enkephalin content. RESULTS: Greater methionine-enkephalin content was measured in the right ventricles of the patients suffering from recent cyanotic spells compared with those with no recent spells (cyanotic spells: 2418 ± 844 pg/g wet weight tissue, n= 6; no spells: 1175 ± 189 pg/g wet weight tissue, n= 14, P= 0.04). An inverse correlation was evident between the arterial oxygen saturation and myocardial methionine-enkephalin content. CONCLUSION: Myocardial methionine-enkephalin levels increase with the severity of hypoxic stress in congenital cardiac disease and may play an important adaptive role in countering adrenergic over-activity and related excess demand on myocardial metabolic capacity.
BACKGROUND: Cardiac opioid peptides have been identified to exert important adaptive metabolic signalling for cardioprotection against ischaemia or hypoxia-related injury. AIMS: To determine myocardial methionine-enkephalin content in children with hypoxemic congenital heart defects and to correlate myocardial content of methionine-enkephalin with the extent of arterial oxygen desaturation. METHODS:Children (n= 20, median age of 16 months), undergoing cardiac surgical repair (tetralogy of Fallot, 17/20), were included in this study. Arterial oxygen saturation was measured on admission. Myocardial samples obtained during surgery were assayed via radioimmunochemistry for methionine-enkephalin content. RESULTS: Greater methionine-enkephalin content was measured in the right ventricles of the patients suffering from recent cyanotic spells compared with those with no recent spells (cyanotic spells: 2418 ± 844 pg/g wet weight tissue, n= 6; no spells: 1175 ± 189 pg/g wet weight tissue, n= 14, P= 0.04). An inverse correlation was evident between the arterial oxygen saturation and myocardial methionine-enkephalin content. CONCLUSION: Myocardial methionine-enkephalin levels increase with the severity of hypoxic stress in congenital cardiac disease and may play an important adaptive role in countering adrenergic over-activity and related excess demand on myocardial metabolic capacity.
Authors: Salvatore Pepe; Norman Y Liaw; Michele Hepponstall; Freya L Sheeran; Matthew S Yong; Yves d'Udekem; Michael M Cheung; Igor E Konstantinov Journal: J Am Heart Assoc Date: 2013-05-10 Impact factor: 5.501