Effect of electroconvulsive therapy on p-GluR1 and p-CaMK Ⅱ α expression under small dose ketamine combined with propofol anesthesia in depressed rats / 中华麻醉学杂志

ABSTRACT

Objective To evaluate the effect of electroconvulsive therapy (ECT) on the expression of phosphorylated glutamate receptor 1 (p-GluR1) and Ca2+/calmodulin-dependent protein kinase Ⅱ α (p-CaMK Ⅱ α) under small dose ketamine combined with propofol anesthesia in the depressed rats.Methods Forty healthy adult male Sprague-Dawley rats,weighing 200-250 g,aged 2-3 months,were used in this study.Mental depression was induced by exposing the animals to chronic unpredictable mild stress (CUMS).Forty mentally depressed rats were divided randomly into 5 groups (n =8 each) using a random number tableM0-4 groups.Propofol 80 mg/kg and ketamine 10 mg/kg were injected intraperitoneally in M0-4 groups.After disappearance of righting reflex,M1-4 groups received ECT of 60,120,180 and 240 mC once a day for 7 consecutive days,respectively,by means of a current (frequency 50 Hz,sine-wave,pulse width 0.7 ms,1-s duration) delivered via ear-clip electrodes,while group M0 received ECT of no quantity of electric charge via ear-clip electrodes.Before CUMS,at 1 day after CUMS and at 1 day after ECT,sucrose preference test was applied to evaluate the depressive behavior.The sucrose preference percentage (SPP) was calculated.At 4 days after CUMS and 4 days after ECT,the learning and memory function was assessed using Morris water maze test.The rats were then sacrificed,and hippocampi were isolated to detect the expression of GluR1,p-GluRl,CaMK Ⅱ α and p-CaMK Ⅱ α by Western blot.Results The SPP was significantly lower after CUMS than before CUMS in M0-4 groups (P＜0.05).Compared with that after CUMS,the SPP was significantly increased,the escape latency was shortened,and the space exploration time was prolonged after ECT in M1-4 groups (P＜0.05).There was no significant difference in SPP after ECT between M1-4 groups (P＞0.05).Compared with group M0,the SPP was significantly increased,and the expression of pGluR1 and p-CaMK Ⅱ α was up-regulated in M1-4groups (P＜0.05).Compared with group M2,the escape latency was significantly prolonged,the space exploration time was shortened,and the expression of pGluR1 and p-CaMK Ⅱ α was down-regulated after ECT in the other groups (P＜0.05).There was no significant difference in GluR1 and CaMK Ⅱ α expression after ECT between the five groups (P＞ 0.05).Conclusion ECT can induce cognitive decline when applied for anti-depression under small dose ketamine combined with propofol anesthesia,and the mechanism is related to increased phosphorylation of GluR1 and CaMK Ⅱ α expression in rats.