| Budget Amount *help |
¥2,000,000 (Direct Cost: ¥2,000,000)
Fiscal Year 1996: ¥1,100,000 (Direct Cost: ¥1,100,000)
Fiscal Year 1995: ¥900,000 (Direct Cost: ¥900,000)
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| Research Abstract |
The effects of volatile anesthetics on ischemia/reperfusion injury in rabbit heart. First, we determined whether three commonly used general anesthetics alter the magnitude of infarction limitation achieved with ischemia and reperfusion. A second aim of this study was to assess the effect of sevoflurane on preconditioning response in rabbits and to determine if the ischemic preconditioning in sevoflurane anesthetized rabbits is blocked by glibenclamide, a specific ATP -sensitive potassium channel antagonist.
(Methods) New Zealand rabbits were intramuscularly initially anesthetized Ketamine (35mg/Kg) and xylazine (5mg/Kg). Tracheotomy was performed and rabbits were intubated with un cuffed endotracheal tube and ventilated with room air and 100% oxygen using mechanical ventilator. Anesthesia was maintatined with ketamine/xylazine i.v. (control), sevoflurane (2.1%, end expiratory), isoflurane (1.2%), and halothane (1.0%). Rabbits were subjected to 30 min of LAD occlusion and 3 hrs reperfus
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ion. Some animals were preconditioned by a 5min LAD occlusion and 10 min reperfusion prior to prolonged ischemia and reperfusion. During experiments, arterial blood pressure, heart rate, and an electrocarbiogram were continually monotored. Area at risk was delineated by injection of evan's blue and infarct size determined by tetrazolium staining. As a result, infarct size was significantly reduced in sevoflurane, halothane and isoflurance anesthetized rabbits as compared with ketamine/xylazine anesthetized rabbits. Preconditioning produced a 56% reduction in infarct size for sevoflurane anesthetized rabbits. Treatment with glibenclamide in preconditioned rabbits resulted in a significant increase in the infarct size.
(Conclusion) 1. These results suggest that volatile anesthetics have myocardial protecctive effect as compared with ketamine/xylazine anesthsia. 2. It was suggested that preconditioning response of the heart is preserved in rabbit hearts anesthetized with sevoflurane. Moreover, blockade of this response by glibenclamide suggest that the preconditioning is mediated by opening of ATP-sensitive potassium channel Less
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