Effect of neurotrophin-3 on Akt expression during ropivacaine-induced neurotoxicity to spinal cord of rats / 中华麻醉学杂志

ABSTRACT

Objective To evaluate the effect of neurotrophin-3 (NT-3) on the expression of serine/threonine protein kinase (Akt) during ropivacaine-induced neurotoxicity to the spinal cord of rats.Methods Healthy adult male Sprague-Dawley rats,aged 1-2 months,weighing 280-320 g,were used in the study.A catheter was inserted at L5,6 interspace into the epidural space of rats.A total of 108 rats,in which intrathecal catheters were successfully implanted,were randomly divided into 3 groups (n =36each)control group (group C),1％ ropivacaine group (group R),and 1％ ropivacaine + NT-3 group (group NT).The equal volume of normal saline was given in group C,1％ ropivacaine 0.12 ml/kg was injected via the intrathecal catheter once every 1.5 h for 8 times in total in R and NT groups.In addition,NT-3 0.1 mg/kg was simultanenously injected via the intrathecal catheter in group NT.On days 1,3,5,7,14 and 28 after the end of administration (T1-6),6 rats were sacrificed in each group.Their lumbar enlargements were removed for determination of neuronal apoptosis (using TUNEL) and Akt expression (by immuno-histochemistry).The apoptotic rate was calculated.Results Compared with group C,the apoptotic rate was significantly increased at T1-4,and Akt expression was significantly up-regulated at T1-3 in group R,and the apoptotic rate were significantly increased,and Akt expression was significantly up-regulated at T1-3 in group NT (P＜0.05).Compared with group R,the apoptotic rate was significantly decreased at T3,4,and Akt expression was significantly down-regulated at T2.3 in group NT (P＜0.05).Conclusion The mechanism by which NT-3 reduces ropivacaine-induced neurotoxicity to the spinal cord may be related to down-regulation of the expression of Akt in rats.