Effect of the shenxiong glucose injection on the recovery of neural function and the expression of AQP-4 in rats after spinal cord injury

Abstract

Objective To explore the action mechanism of shenxiong glucose injection in treatment of acute spinal cord injury(SCI) through observing its effects on the recovery of motor function and the expression of aquaporin-4(AQP-4) in SCI rats.Methods Totally 90 healthy,aduh,Sprague-Dawley rats were randomly divided into a sham operation group (n=30),aSCI group (n=30) and a drug group (n=30).The SCI rat models in both the SCI group and the drup group were established aecording to the modified Allen's method,while the sham operation group was only given laminectomy.After the operation,the drug group was given intraperitoneal shenxiong glucose injection of 30 rnl/kg a day,while the other two groups were injected in the same way with normal saline.The neural function recovery,the pathological changes after SCI and the expressions of AQP-4 were observed 1,3,7,14 and 21 d after the operation using the Tarlov score,the hematoxylin and eosin staining,as well as immunofluorescence techniques and Western blotting.And the correlation of Tarlov scores with AQP-4 expressions was analyzed.Results No significant changes in Tarlov scores were observed in the sham operation group (P ＞ 0.05),while in the SCI group and the drug group,postoperative Tarlov scores decreased significantly.The hindlimb nerve function recovered to some degree with time in the SCI group and drug group.At 3,7,14 and 21 days after the operation,the Tarlov scores in the drug group were significantly higher than the SCI group (P ＜ 0.05).The drug group showed less severe pathological changes,with more residual neurons still visible of nucleoli than the SCI group 21 days after the operation.Compared with the sham operation group,the expression levels of AQP-4 were significantly higher in the SCI group and drug group at all the time points (P ＜ 0.05).However,the expression levels of AQP-4 in the drug group were significantly lower than the SCI group accordingly (P ＜ 0.05).The Tarlov scores were found to be significantly and negatively related to the AQP-4 protein expression levels 3 days(r =-0.523,P =0.003),7 days(r =-0.437,P=0.016),14 days(r=-0.417,P=0.022) and 21 days(r=-0.377,P=0.040)after the operation.Conclusion Injecting shenxiong with glucose can effectively promote the recovery of motor function after SCI,at least in rats.And its mechanism may be that the development of spinal cord edema is prevented and the secondary spinal cord injury alleviated by restraining the expressions of AQ P-4 in the injured areas. Key words: Shenxiong glucose injection; Spinal cord injury; AQP-4; Tarlov score