电磁辐射对大鼠小脑蛋白激酶C活性及谷氨酸受体2蛋白质磷酸化的影响

Effects on activation of protein kinase C and phosphorylation of glutamate receptor 2 by electromagnetic irradiation in rat cerebellum

目的研究电磁辐射对大鼠小脑蛋白激酶C(PKC)活性和谷氨酸受体2(GluR2)蛋白质磷酸化的影响,探讨电磁辐射对小脑运动性学习记忆的神经信号传导通路的损伤特点。方法将60只健康成年雄性Wistar大鼠分为对照组10只和辐射组50只,辐射组又根据观察时间点分为辐射后0,3,12,24和72 h等5个亚组,每亚组10只。各辐射组给予90 mW/cm^2的电磁辐射20 min。测定电磁辐射后即刻大鼠的肛温,并计算比吸收率(SAR)值;采用改良的TaKai法检测PKC的活性,采用Western blot方法检测小脑GluR2蛋白质及其磷酸化水平。结果电磁辐射后即刻,大鼠肛温升高2.99℃,SAR值为8.66 W/kg。大鼠小脑PKC的活性在电磁辐射后即刻显著降低;GluR2的表达水平在各观察时间点均无显著变化,但GluR2的磷酸化水平在电磁辐射后即刻显著降低,其他观察时间点无显著变化。结论电磁辐射能够显著降低大鼠小脑PKC的活性和GluR2的磷酸化水平,从而对运动性学习记忆的神经信号传导通路产生损伤效应。

Objective To investigate the effects of electromagnetic irradiation on activation of protein kinase C （PKC） and phosphorylation of glutamate receptor 2 （GluR2） in rat cerebellum. Methods Sixty male Wistar rats were divided randomly into a control group and an electromagnetic exposure group （ including 5 subgroups observed at different time points after the irradiation, eg. 0 hour, 3 hours, 12 hours, 24 hours and 72 hours after irradiation）, with 10 rats in each group. All the rats in the exposure group were exposed to 90 mW/cm^2 electromagnetic irradiation for 20 minutes, their rectal temperature was detected immediately after irradiation and the specific absorption rate （SAR）value was calculated, activation of PKC was detected with improved TaKai method, the level of cerebellar GluR2 expression and phosphorylation （ser880） was detected by using Western blot. Results Immediately （0 hour） after exposure, the rectal temperature of rats increased 2.99℃ , SAR value was 8.66 W/kg. When compared to the control group, it was found that there was no significant difference between the exposure group and the control group with regard to all the parameters at 3, 12, 24 and 72 hours after exposure, except that the cerebellar PKC activation and GluR2 （ser 880）phosphorylation decreased significantly immediately after irradiation. Conclusion The electromagnetic irradiation has injurious effects on cerebellar signal pathway of for motor learning.