Effects of dexmedetomidine pretreatment on expression of TFAM and SDHA during lung ischemia-reperfusion in mice / 中华麻醉学杂志

ABSTRACT

Objective To evaluate the effect of dexmedetomidine pretreatment on the expression of mitochondrial transcription factor A ( TFAM) and succinate dehydrogenase ( SDHA) during lung ischemia-reperfusion ( I∕R) in mice. Methods Twenty-four clean-grade healthy male C57BL∕6J mice, aged 8-10 weeks, weighing 18-22 g, were divided into 3 groups ( n=8 each) using a random number table method:sham operation group ( group S ) , lung I∕R group ( group I∕R ) and dexmedetomidine pretreatment group ( group D) . In I∕R and D groups, lung I∕R was induced by clamping the left pulmonary hilum for 60 min followed by 120-min reperfusion in anesthetized mice. The chest was only opened, but the left pulmonary hilum was not occluded in group S. Dexmedetomidine 25μg∕kg was intraperitoneally injected at 30 min be-fore ischemia in group D, while the equal volume of normal saline was given instead of dexmedetomidine in I∕R and S groups. The mice were sacrificed at 120 min of reperfusion, and lungs were removed for determi-nation of wet∕dry weight ratio ( W∕D ratio) , cell apoptosis ( by TUNEL) and expression of TFAM and SDHA mRNA in lung tissues ( by real-time polymerase chain reaction ) and for examination of the pathological changes of lung tissues. The apoptosis index was calculated. Results Compared with group S, the W∕D ratio, apoptosis index and lung injury scores were significantly increased, and the expression of TFAM and SDHA mRNA was down-regulated in I∕R and D groups ( P<0. 05) . Compared with group I∕R, the W∕D ra-tio, apoptosis index and lung injury scores were significantly decreased, and the expression of TFAM and SDHA mRNA was up-regulated in group D ( P<0. 05) . Conclusion The mechanism by which dexmedeto-midine pretreatment attenuates lung I∕R injury is related to up-regulating the expression of TFAM and SDHA in mice.