title: Remote ischemic conditioning provides humoural cross-species cardioprotection through glycine receptor activation.
abstract: Remote ischaemic conditioning (RIC) releases a humoural factor able to exert cross-species cardioprotection when plasma dialysate is applied to isolated hearts. However, the exact chemical nature of this factor is currently unknown.
  
  
  
  RIC (4 × 5min femoral occlusion/5min reperfusion) was applied to 10 male pigs, and blood was taken before and after the manoeuvre. Discriminant analysis of1H-NMR spectra (n = 10-12) obtained from plasma dialysates (12-14 kDa cut-off) allowed to demonstrate a different metabolic profile between control and postRIC samples, with lactate (2.671 ± 0.294 vs. 3.666 ± 0.291 μmol/mL, P = 0.020), succinate (0.062 ± 0.005 vs. 0.082 ± 0.008 μmol/mL, P = 0.035) and glycine (0.055 ± 0.009 vs. 0.471 ± 0.151 μmol/mL, P = 0.015) being the main responsible for such differences. Plasma dialysates were then given to isolated mice hearts submitted to global ischaemia (35 min) and reperfusion (60 min), for 30 min before ischaemia or during the first 15 min of reflow. Infarct size was significantly reduced when postRIC dialysate was applied before ischaemia as compared with hearts pretreated with control dialysate (44.81 ± 3.22 vs. 55.55 ± 2.53%, P = 0.012, n = 12). Blockade of glycine receptors with strychnine 10 μM inhibited the protective effect caused by pretreatment with postRIC dialysate (52.76 ± 6.94 vs. 51.92 ± 5.78%, P-NS, n = 5), whereas pretreatment with glycine 3 mmol/L, but not succinate 100 μmol/L, mimicked RIC protection (41.90 ± 4.50% in glycine-treated vs. 61.51 ± 5.16 and 64.73 ± 4.47% in succinate-treated and control hearts, respectively, P < 0.05, n = 4-7).
  
  
  
  RIC releases glycine and exerts cross-species cardioprotection against infarction through glycine receptor activation.
authors.affiliation: Cardiovascular Diseases Research Group, Department of Cardiology, Vall d'Hebron University Hospital and Research Institute, Universitat Autònoma de Barcelona, Pg Vall d'Hebron 119-129, 08035 Barcelona, Spain.
authors.forename: Juan
authors.initials: J
authors.lastname: José Alburquerque-Béjar
authors.affiliation: Cardiovascular Diseases Research Group, Department of Cardiology, Vall d'Hebron University Hospital and Research Institute, Universitat Autònoma de Barcelona, Pg Vall d'Hebron 119-129, 08035 Barcelona, Spain.
authors.forename: Ignasi
authors.initials: I
authors.lastname: Barba
authors.affiliation: Cardiovascular Diseases Research Group, Department of Cardiology, Vall d'Hebron University Hospital and Research Institute, Universitat Autònoma de Barcelona, Pg Vall d'Hebron 119-129, 08035 Barcelona, Spain.
authors.forename: Laura
authors.initials: L
authors.lastname: Valls-Lacalle
authors.affiliation: Cardiovascular Diseases Research Group, Department of Cardiology, Vall d'Hebron University Hospital and Research Institute, Universitat Autònoma de Barcelona, Pg Vall d'Hebron 119-129, 08035 Barcelona, Spain.
authors.forename: Marisol
authors.initials: M
authors.lastname: Ruiz-Meana
authors.affiliation: Cardiovascular Diseases Research Group, Department of Cardiology, Vall d'Hebron University Hospital and Research Institute, Universitat Autònoma de Barcelona, Pg Vall d'Hebron 119-129, 08035 Barcelona, Spain.
authors.forename: Michela
authors.initials: M
authors.lastname: Pecoraro
authors.affiliation: Cardiovascular Diseases Research Group, Department of Cardiology, Vall d'Hebron University Hospital and Research Institute, Universitat Autònoma de Barcelona, Pg Vall d'Hebron 119-129, 08035 Barcelona, Spain dgdorado@vhebron.net antonio.rodriguez.sinovas@vhir.org.
authors.forename: Antonio
authors.initials: A
authors.lastname: Rodríguez-Sinovas
authors.affiliation: Cardiovascular Diseases Research Group, Department of Cardiology, Vall d'Hebron University Hospital and Research Institute, Universitat Autònoma de Barcelona, Pg Vall d'Hebron 119-129, 08035 Barcelona, Spain dgdorado@vhebron.net antonio.rodriguez.sinovas@vhir.org.
authors.forename: David
authors.initials: D
authors.lastname: García-Dorado
mesh_terms: D000818:Animals; D015415:Biomarkers / Q000097:blood; D016002:Discriminant Analysis; D004195:Disease Models, Animal; D018691:Excitatory Amino Acid Antagonists / Q000494:pharmacology; D005263:Femoral Artery / Q000601:surgery*; D005998:Glycine / Q000097:blood* / Q000494:pharmacology; D019194:Ischemic Preconditioning / Q000379:methods*; D008026:Ligation; D008297:Male; D008810:Mice, Inbred C57BL; D017202:Myocardial Ischemia / Q000097:blood / Q000473:pathology / Q000503:physiopathology / Q000517:prevention & control*; D015428:Myocardial Reperfusion Injury / Q000097:blood / Q000473:pathology / Q000503:physiopathology / Q000517:prevention & control*; D009206:Myocardium / Q000378:metabolism* / Q000473:pathology; D066244:Proton Magnetic Resonance Spectroscopy; D018009:Receptors, Glycine / Q000819:agonists / Q000037:antagonists & inhibitors / Q000378:metabolism*; D015398:Signal Transduction; D013045:Species Specificity; D034421:Sus scrofa; D013997:Time Factors
chemical_list: D015415:Biomarkers; D018691:Excitatory Amino Acid Antagonists; D018009:Receptors, Glycine; D005998:Glycine
keywords: Glycine; Infarction; Nuclear magnetic resonance; Remote ischaemic conditioning