An ATP-sensitive potassium (KATP) channel opener, nicorandil, lowers the threshold for ischemic preconditioning in barbital-anesthetized dogs. Heart Vessels 1997;Suppl 12:175-7
Date
01/01/1997Pubmed ID
9476575Scopus ID
2-s2.0-0031283361 (requires institutional sign-in at Scopus site) 8 CitationsAbstract
To determine whether the adenosine triphosphate (ATP)-sensitive potassium channel (KATP channel) opener, nicorandil, lowers the threshold for the infarct-reducing effect of preconditioning (PC), barbital-anesthetized dogs were subjected to 60-min occlusion (60'OC) of left anterior descending coronary artery (LAD) followed by 3-h reperfusion (3h-RP). At the end of the 3h-RP, heart was resected to measure infarct size. Infarct size was determined by triphenyltetrazolium chloride (TTC) staining, calculated gravimetrically and was expressed as a percent age of area at risk (AAR). Myocardial blood flow was measured by radioactive microspheres. Single 5-min LAD occlusion 10 min before 60'OC (5'PC group) markedly reduced infarct size, compared to the controls (11.8 +/- 3.7% versus 26.8 +/- 4.7%; P < 0.05). Neither 2.5-min PC (2.5'PC group), nor 2.5-min intracoronary infusion with 0.5 microgram/kg per min of nicorandil followed by a 10-min drug-free period (2.5'NC group), showed a cardioprotective effect (26.5 +/- 1.7% and 20.7 +/- 2.8%, respectively). However, when nicorandil was administered during the 2.5-min LAD occlusion period (2.5'PC + 2.5'NC group), infarct size was significantly reduced to an extent similar to that in 5'PC group (13.6 +/- 1.2%). There were no significant differences in hemodynamics, collateral circulation, or AAR between groups. These results suggest that nicorandil lowers the threshold for the infarct-reducing effect of PC in dogs by, at least in part, activation of myocardial KATP channels.
Author List
Mizumura T, Saito S, Ozawa Y, Kanmatsuse K, Gross GJMESH terms used to index this publication - Major topics in bold
AnimalsBarbital
Dogs
Female
Heart
Ischemic Preconditioning, Myocardial
Male
Niacinamide
Nicorandil
Potassium Channels
Regional Blood Flow
Time Factors
