Effects of nicorandil administration on survival rate and arrhythmias during reperfusion in anesthetized rabbits.
The aim was to study the effects of nicorandil (an ATP-sensitive K+ channel opener) and tolbutamide (an ATP-sensitive K+ channel blocker) on reperfusion-induced arrhythmias in pentobarbitone and ketamine anesthetized rabbits. Arrhythmias were induced by reperfusion for 20 min following a 15-min ligation of the left main coronary artery with a silk ligature. Rabbits were pretreated with nicorandil (0.47, 0.93 or 1.86 mg/kg i.v.) or tolbutamide (180 mg/kg i.p.) or vehicle (dimethylsulfoxide/saline) before the coronary artery occlusion. In the control group (n = 10), only 60% of the animals survived during reperfusion. Intravenous pretreatment with 0.47, 0.93 or 1.86 mg/kg of nicorandil increased the survival rate to 86% (n = 7), 75% (n = 8) and 86% (n = 7), respectively. Nicorandil pretreatment significantly decreased the incidence and duration of reperfusion-induced life-threatening arrhythmias and increased the number of animals that survived without developing any arrhythmia. Tolbutamide pretreatment was associated with a decreased survival rate of 50% (n = 12) and an increase in the incidence and duration of reperfusion-induced arrhythmias. Pretreatment with nicorandil may result in protection against reperfusion-induced arrhythmias and increased survival in anesthetized rabbits.
Das
B
B
Department of Pharmacology, Kasturba Medical College, Manipal, Karnataka, India. mcoms@mos.com.np
Sarkar
C
C
Karanth
K S
KS
D000758:Anesthesia; D000818:Animals; D000889:Anti-Arrhythmia Agents / Q000494:pharmacology*; D001145:Arrhythmias, Cardiac / Q000209:etiology / Q000401:mortality / Q000517:prevention & control*; D004305:Dose-Response Relationship, Drug; D005260:Female; D006339:Heart Rate / Q000187:drug effects; D008297:Male; D017202:Myocardial Ischemia / Q000150:complications; D020108:Nicorandil / Q000494:pharmacology*; D011817:Rabbits; D015427:Reperfusion Injury / Q000150:complications*; D015996:Survival Rate; D013997:Time Factors; D014044:Tolbutamide / Q000494:pharmacology
D000889:Anti-Arrhythmia Agents; D020108:Nicorandil; D014044:Tolbutamide