Effects of ropivacaine in cognitive dysfunction and synapses after tibial fracture in aged rats
Objective To explore the effects of ropivacaine on cognitive dysfunction and synapses in aged rats after tibial fracture.Methods SD male rats were divided into sham operation group,model group and low,medium,high dose experimental groups.Sham operation group was incised and sutured under local anesthesia,and other four groups underwent open tibial fracture operation.Sham operation group and model group were given sevoflurane anesthesia,low,medium and high dose experimental groups were given 0.5,1.0,2.0 mg·kg-1 ropivacaine on the basis of sevoflurane anesthesia.Open field test and Morris water maze test were performed 7 days after operation;Longa score was evaluated;neurotransmitter levels were detected by kit;and Syn1 in hippocampus of rats was detected by immunohistochemistry.Western blot analysis was used to detected the expression of N-methyl-D-aspartate receptor 2B(NMDAR2B),calmodulin-dependent protein kinase Ⅱ(CaMK Ⅱ)and Syn1.Results The Longa scores of sham operation group,model group and low,medium,high dose experimental groups were 0,(3.50±0.71),(2.80±0.63),(2.20±0.63)and(0.90±0.32)points;the integrated optical density of Syn1 were 0.56±0.09,0.25±0.03,0.34±0.03,0.42±0.03 and 0.50±0.05;the expression of Syn1 protein were 1.08±0.12,0.42±0.05,0.55±0.07,0.72±0.06 and 0.86±0.05;the expression of NMDAR2B protein were 1.28±0.13,0.51±0.07,0.69±0.06,0.84±0.07 and 1.02±0.11;CaMK Ⅱ protein were 0.94±0.08,0.36±0.04,0.50±0.06,0.71±0.06 and 0.86±0.06.There were statistically significant differences between sham operation group and model group(P<0.05);there were significant differences in the above indexes between model group and low,medium,high dose experimental groups(all P<0.05).Conclusion Ropivacaine can improve cognitive dysfunction and synapses in aged rats after tibial fracture.