溴氰菊酯对大鼠脑神经细胞凋亡及Caspase-3表达的影响

Effects of deltamethrin on the apoptosis and the expression of caspase-3 in rat neural cells

目的 研究Caspase-3在溴氰菊酯(deltamethrin,DM)诱导大鼠脑神经细胞凋亡机制中的作用。方法 成年雄性Wistar大鼠腹腔注射12.5 mg/kg的DM染毒,并分成不同时间观察组;以FACS420型流式细胞仪测定大鼠海马和皮层细胞凋亡率和Caspase-3蛋白的表达;以四肽化合物Ac-DEVD-pNa为底物测其神经细胞Caspase-3活力。结果 DM染毒后24 h、48 h、5 d组大鼠海马、皮层神经细胞凋亡率[海马:(8.45±1.02)％、(9.44±1.14)％、(7.58±0.75)％,皮层:(7.90±0.49)％、(8.01±0.87)％、(7.97±0.41)％]均高于对照组[海马:(2.97±0.36)％,皮层:(3.50±0.48)％],差异有统计学意义(P<0.01),而5 h组未见明显变化;DM染毒后5、24、48 h,大鼠海马、皮层神经细胞Caspase-3活力(A405nm吸光度值,海马:0.389±0.038、0.472±0.041、0.295±0.049,皮层:0.321±0.068、0.429±0.077、0.344±0.047)与5 d组大鼠海马Caspase-3活力(0.246±0.065)均明显高于对照组(海马:0.184±0.054,皮层:0.198±0.049),差异有统计学意义(P<0.05,P<0.01);DM染毒后5、24、48h,大鼠脑组织Caspase-3蛋白表达亦明显高于对照组,5 d组未见明显变化。结论DM可影响大鼠脑海马和皮层神经细胞凋亡率、Caspase-3活力及蛋白表达;

Objective To study the effect of deltamethrin on the apoptotic rate and the expression of caspase-3 in rat neural cells. Methods Male Wistar rats were randomly divided into 5 groups: control ,5 h, 24 h, 48 h and 5 d exposed groups. Apoptotic rate and the expression of caspase-3 were measured by FACS420 Flow Cy-tometer; Ac-DEVD-pNa was used as a substrate to detect the activity of caspase-3. Results Apoptotic rates in 24 h,48 h and 5 d exposed groups in hippocampus and cerebral cortex[ hippocampus:(8.45 ± 1. 02)% , (9.44 ± 1.14)%,(7.58±0.75)%;cerebral cortex: (7.90 ± 0.49)% , (8.01 ± 0.87)% , (7.97 ± 0.41) % respectively] were higher than those in the control[hippocampus:(2.97 ± 0. 36)%; cerebral cortex: (3 . 50 ± 0.48)% ] (P < 0.01); the activity of caspase-3 in 5 h,24 h and 48 h exposed groups( A405nm in hippocampus: 0.389 ± 0.038,0.472 ±0.041,0.295 ±0.049; A405nm in cerebral cortex:0.321 ± 0.068,0.429 ± 0.077,0.344 ± 0.047) and 5 d group of hippocampus(0.246 ± 0.065) were all higher than those of the control(hippocampus:0.184 ± 0.054;cerebral cortex:0.198 ±q 0.049)(P < 0.05,P < 0.01);the expression of caspase-3 in 5 h,24 h and 48 h exposed groups increased apparently while 5 d group did not. Conclusion Exposure to high dose of deltamethrin would affect the apoptosis, the activity and expression of caspase-3 in rat neural cells. The increase in caspase-3 activity and expression occurred before the rising of neuronal apoptotic rate may be the upstream event of apoptosis.