Effects of repeated intraperitoneal dexmedetomidine on cognitive function in rats with chronic cerebral ischemia / 中华麻醉学杂志

ABSTRACT

Objective To investigate the effects of repeated intraperitoneal dexmedetomidine on the cognitive function in rats with chronic cerebral ischemia.Methods Forty-eight male Sprague-Dawley rats,aged 3-4months,weighing 250-300 g,were randomly divided into 4 groups (n =12 each) ∶ sham operation group (group S),chronic cerebral ischemia group (group IS),dexmedetomidine treatment 1 group (group DXM1) and dexmedetomidine treatment 2 group (group DXM2).Dexmedetomidine 5 μg/kg was injected intraperitoneally at 30 min before occlusion of bilateral common carotid arteries and 3,12,24 and 48 h after occlusion in group DXM1,and at 3,12,24 and 48 h after occlusion in group DXM2.The cognitive function was assessed by Morris water maze 2 weeks after occlusion.The apoptosis was examined by TUNEL.The expression of Bcl-2 protein in hippocampus was detected by Western blot.Results Compared with group S,the escape latency was significantly prolonged from 2nd day to 5th day after the place navigation test in group IS and on 2nd day after Morris water maze test in groups DXM1 and DXM2,and the time of staying in 1 st quadrant was significantly shortened,the apoptotic rate was increased,and the expression of Bcl-2 was up-regulated in groups IS,DXM1 and DXM2 (P ＜ 0.05).Compared with group IS,the escape latency was significantly shortened from 3rd day to 5th day after the place navigation