title: Ranolazine as a cardioplegia additive improves recovery of diastolic function in isolated rat hearts.
abstract: BACKGROUND
  Ranolazine (Ran), an antianginal agent, inhibits late Na(+) current. The purpose of this study was to determine whether there was an added benefit of adding Ran to cardioplegia (CP) in a model of global ischemia/reperfusion.
  
  
  RESULTS
  Isolated rat hearts were Langendorff-perfused and exposed to 40-minute normothermic, cardioplegic global ischemia and 30 minutes of reperfusion. Before ischemia and during reperfusion, hearts were treated with no drug (control) or with the late Na(+) current inhibitors Ran (5 micromol/L) or tetrodotoxin (1 micromol/L). Ischemic cardioplegic arrest led to an increase of left ventricular end-diastolic pressure (LVEDP) by > or =20 mm Hg (ie, cardiac contracture). Ten out of 11 hearts treated with CP alone developed contracture, whereas 6 out of 11 hearts treated with CP plus Ran developed contracture. Ran added to CP reduced LVEDP at the end of ischemia from 41+/-5 mm Hg in CP alone to 26+/-3 mm Hg in CP plus Ran (P=0.024). Area under the curve for LVEDP during the entire ischemic period was also smaller in CP plus Ran versus CP alone. The percent increase (from baseline) of LVEDP measured at the end of 30-minute reperfusion was smaller for CP plus Ran (66+/-18%) versus CP alone (287+/-90%; P=0.035). The area under the curve for LVEDP during reperfusion was smaller in CP plus Ran versus CP alone. Tetrodotoxin (1 micromol/L) also reduced cardiac contracture during ischemia/reperfusion, compared to CP alone.
  
  
  CONCLUSIONS
  Our results suggest that Ran may have therapeutic potential as an adjunct to CP and further support a protective role of Na(+) current inhibition during ischemia/reperfusion.
authors.affiliation: The Heart Institute, Good Samaritan Hospital, Los Angles, CA 90017, USA.
authors.forename: Hyosook
authors.initials: H
authors.lastname: Hwang
authors.forename: Joseph M
authors.initials: JM
authors.lastname: Arcidi
authors.forename: Sharon L
authors.initials: SL
authors.lastname: Hale
authors.forename: Boris Z
authors.initials: BZ
authors.lastname: Simkhovich
authors.forename: Luiz
authors.initials: L
authors.lastname: Belardinelli
authors.forename: Arvinder K
authors.initials: AK
authors.lastname: Dhalla
authors.forename: John C
authors.initials: JC
authors.lastname: Shryock
authors.forename: Robert A
authors.initials: RA
authors.lastname: Kloner
mesh_terms: D000083:Acetanilides / Q000494:pharmacology*; D000787:Angina Pectoris / Q000188:drug therapy*; D000818:Animals; D003971:Diastole / Q000187:drug effects*; D005260:Female; D006324:Heart Arrest, Induced; D009200:Myocardial Contraction / Q000187:drug effects; D017202:Myocardial Ischemia / Q000503:physiopathology; D010879:Piperazines / Q000494:pharmacology*; D000069458:Ranolazine; D051381:Rats; D017207:Rats, Sprague-Dawley; D012964:Sodium / Q000378:metabolism; D013779:Tetrodotoxin / Q000494:pharmacology
chemical_list: D000083:Acetanilides; D010879:Piperazines; D013779:Tetrodotoxin; D012964:Sodium; D000069458:Ranolazine