title: Therapeutic hypothermia activates the endothelin and nitric oxide systems after cardiac arrest in a pig model of cardiopulmonary resuscitation.
abstract: Post-cardiac arrest myocardial dysfunction is a major cause of mortality in patients receiving successful cardiopulmonary resuscitation (CPR). Mild therapeutic hypothermia (MTH) is the recommended treatment after resuscitation from cardiac arrest (CA) and is known to exert neuroprotective effects and improve short-term survival. Yet its cytoprotective mechanisms are not fully understood. In this study, our aim was to determine the possible effect of MTH on vasoactive mediators belonging to the endothelin/nitric oxide axis in our porcine model of CA and CPR. Pigs underwent either untreated CA or CA with subsequent CPR. After state-of-the-art resuscitation, the animals were either left untreated, cooled between 32-34 °C after ROSC or treated with a bolus injection of S-PBN (sodium 4-[(tert-butylimino) methyl]benzene-3-sulfonate N-oxide) until 180 min after ROSC, respectively. The expression of endothelin 1 (ET-1), endothelin converting enzyme 1 (ECE-1), and endothelin A and B receptors (ETAR and ETBR) transcripts were measured using quantitative real-time PCR while protein levels for the ETAR, ETBR and nitric oxide synthases (NOS) were assessed using immunohistochemistry and Western Blot. Our results indicated that the endothelin system was not upregulated at 30, 60 and 180 min after ROSC in untreated postcardiac arrest syndrome. Post-resuscitative 3 hour-long treatments either with MTH or S-PBN stimulated ET-1, ECE-1, ETAR and ETBR as well as neuronal NOS and endothelial NOS in left ventricular cardiomyocytes. Our data suggests that the endothelin and nitric oxide pathways are activated by MTH in the heart.
authors.affiliation: Department of Surgical Sciences/Anesthesiology and Intensive Care, Uppsala University, Uppsala, Sweden.
authors.forename: Frank
authors.initials: F
authors.lastname: Zoerner
authors.forename: Lars
authors.initials: L
authors.lastname: Wiklund
authors.forename: Adriana
authors.initials: A
authors.lastname: Miclescu
authors.forename: Cecile
authors.initials: C
authors.lastname: Martijn
mesh_terms: D000818:Animals; D016282:Aspartic Acid Endopeptidases / Q000235:genetics / Q000378:metabolism; D001557:Benzenesulfonates / Q000494:pharmacology; D016887:Cardiopulmonary Resuscitation; D002317:Cardiovascular Agents / Q000494:pharmacology; D019332:Endothelin-1 / Q000235:genetics / Q000378:metabolism*; D015870:Gene Expression / Q000187:drug effects; D005786:Gene Expression Regulation; D006323:Heart Arrest / Q000378:metabolism / Q000628:therapy*; D007036:Hypothermia, Induced; D015428:Myocardial Reperfusion Injury / Q000378:metabolism / Q000517:prevention & control; D009206:Myocardium / Q000378:metabolism; D009569:Nitric Oxide / Q000378:metabolism*; D019001:Nitric Oxide Synthase / Q000235:genetics / Q000378:metabolism; D017466:Receptors, Endothelin / Q000235:genetics / Q000378:metabolism; D034421:Sus scrofa
chemical_list: D001557:Benzenesulfonates; D002317:Cardiovascular Agents; D019332:Endothelin-1; D017466:Receptors, Endothelin; D009569:Nitric Oxide; D019001:Nitric Oxide Synthase; D016282:Aspartic Acid Endopeptidases