Referenced in: none

Automatically associated channels: Kir2.3

Title: [Cardioprotective effects of K(ATP) channel opener nicorandil during ischemia/ reperfusion in dogs]

Authors: Li Feng, Jian Qiu, Jun Ma, Xiao-bo Huang, Dao-gang Cha, Jian-ping Bin

Journal, date & volume: Zhongguo Wei Zhong Bing Ji Jiu Yi Xue, 2005 Mar , 17, 157-60

PubMed link: http://www.ncbi.nlm.nih.gov/pubmed/15760526

Abstract
To further confirm the effect of nicorandil in reducing the area of myocardial infarct is through the mediation of activation of the KATP channel but not by its nitrate-like properties, and to determine whether the protective effect is the same or not when the drug is either given immediate after infarction or after reperfusion.Thirty-five dogs were randomly divided into five groups as follows. Ischemia/reperfusion (IR) group: the dogs were subjected to 90 minutes of left anterior descending coronary artery(LAD) occlusion followed by 120 minutes reperfusion. Pre-nicorandil (PNIC) group: nicorandil(NIC) 100 microg/kg was administrated by intravenous injection 10 minutes before occlusion, followed by infusion of 10 microg x kg(-1) x min (-1) of the drug till the end of reperfusion. Ischemia nicorandil(INIC) group: NIC 100 microg/kg was administered by intravenous injection 15 minutes after occlusion and 10 microg x kg(-1) x min (-1) of drug intravenously till the end of reperfusion. In the Onset reperfusion treated with nicorandil(RNIC) group: NIC 100 microg/kg was administered intravenously at the onset of reperfusion followed by 10 microg x kg(-1) x min (-1)of drug intravenously up to the end of reperfusion. Glibenclamide(GLIB)+INIC group: before NIC was administered, dogs were pretreated with GLIB 0.3 mg/kg for 10 minutes, and other treatment was the same as INIC group. Hemodynamics data were determined as baseline, 60 minutes post-occlusion, and 120 minutes post-reperfusion. By using 2, 3, 5-triphenyltetrazolium chloride (TTC) staining, the infarct areas were analyzed with image analyzer.The results showed that at 60 minutes post-occlusion, cardiac output (CO) was reduced in every group compared with baseline (all P<0.01), CO value recovered at 120 minutes after reperfusion in both PNIC and INIC group (P>0.05). There were no significant differences in heart rate (HR), mean artery pressure(MAP), mean pulmonary artery pressure(MPAP), pulmonary capillary wedge pressure(PCWP) values among all the groups. A marked reduction in the infarct area was found in PNIC group and INIC group (P<0.01) compared with IR group. Administration of GLIB before INIC shows to have no protective effect (P>0.05).Our study shows that nicorandil which is a K ATP channel activator, could mimic the effect of ischemic pre-conditioning of the myocardium, by reducing the area of myocardial infarct.