The expression of aldose reductase and therapeutic benefits of their inhibition in rats injuried spinal cord

Abstract

Objective To discuss the expression of Aldose reductase in acute spinal cord injury and the effect of Aldose reductase inhibitor on spinal cell apoptosis.Methods One hundred and fifty SD adult rats were randomly assigned to sham group (n =50),acute spinal cord injury (n =50 ),Aldose reductase inhibitor (Epalrestat Tablets) group (n =50),each group is divided into five sub- groups(6,12,24,48,72 h sub-groups).In the sham group,only laminectomy was applied; In the SCI group and the ARI group,the model were made by Allen' s method.The pathological changes in injured spinal cord were observed with hematoxylin and eosin staining.The aldose reductase was detected by Elisa methods.The TdTmediated dUTP nick end labeling (TUNEL) method was employed to determine neuronal apoptosis.Results After injury 6,12,24,48 and 72 h,the grey and white matter structure of damage area were damaged,with cavity forming and inflammatory cells infiltrating.The degree of ARI group was lighted than SCI group.The content of aldose reductase in the sham operation group after injury 3,12,24,48,72 h were (10.75 ±0.47),(10.61 ±0.44),(10.62±0.55),(10.92±0.49),(10.57±0.52) U/L,the AR contents of SCI group at corresponding time were ( 12.17 ± 0.65 ),( 14.09 ± 0.61 ),( 14.58 ± 0.72 ),( 15.45 ±0.47 ),( 15.33 ± 0.29 ) U/L,and the AR content of the ARI group at corresponding time were ( 10.84 ±0.21),(12.70±0.47),(12.84±0.55),(12.28±0.54),(11.95±0.90) U/L.The AR content of the SCI group at each time point were significantly higher than the shame operation group and ARI group ( P ＜0.05 ).The spinal cord apoptotic cells were rarely seen in the sham operation group at each time point.The apoptotic rates (％) of SCI group after injuried 3,12,24,48,72 h were were 8.45±0.51,27.38 ± 3.19,32.59 ±3.36,39.04 ±4.51,23.48 ±2.40,and the rates of the ARI group at corresponding time were 8.21 ±0.52,18.69 ±1.63,22.64 ±2.18,25.61 ±3.53,16.48 ± 2.23.The neuron apoptosis rates of SCI group at 12,24 、48and 72 h were higher than that of the ARI group (P ＜ 0.05 ).Conclusion After acute spinal cord injury the expression of the AR increased,ARI may reduce the spinal cord neurons cell apoptosis. Key words: Spinal cord injury; Aldose reductase; Cell apoptosis