Effects of insulin-like growth factor-1 on nerve function and expression of vascular endothelial growth factor protein and mRNA after cerebral ischemic reperfusion in rats

Objective To observe dynamically the influence of insulin-like growth factor (IGF)-1 on the nerve function and expression of vascular endothelial growth factor (VEGF) protein and mRNA after cerebral ischemia/reperfusion in rats.Methods SD rats were randomly divided into sham-operated group,cerebral ischemia/reperfusion group,and IGF-1 treated group.The evaluation of ethnology was performed at 12th,24th h,and 3rd,7th day after ischemia-reperfusion,and expression of VEGF protein and mRNA was dected by using immunohistochemistry and reverse transcription-polymerase chain reaction (RT-PCR) respectively.Results The mNSS of rats in IGF-1 treated group at 12th,24th h,and 3rd,7th day after reperfusion was 8.67 ± 1.21,7.50 ± 1.52,4.33 ± 1.03,3.67 ± 1.37 respectively,lower than that in ischemia/reperfusion group (11.00 ± 1.26,9.83 ± 1.33,7.83 ± 1.17,7.17 ± 1.72 respectively,P＜0.05 ).The expression of VEGF protein in IGF-1 treated group was 88.78 ± 6.67,95.83 ± 7.61,26.88 ±4.22,16.30 ±4.69 respectively,higher than that in ischemia/reperfusion group from 12th h to 7th day after reperfusion ( P ＜ 0.05 ).The expression of VEGF mRNA in IGF-1 treated group was 0.474 ± 0.035,0.417 ± 0.044,0.326 ± 0.025 and 0.265 ± 0.040 respectively,higher than that in ischemia/reperfusion group from 12th h to 7th day after reperfusion and there was significant difference between two groups (P ＜0.05 ).Conclusion IGF-1 can alleviate cerebral ischemia/reperfusion injury prohably by regulating the expression of VEGF protein and mRNA,resulting in the improvement of nerve function. Key words: Brain ischemia; Reperfusion injury; Insulin-like growth factor-1 ; Vascular endothelial growth factor