臭氧对PD模型大鼠黑质氧化应激及凋亡相关蛋白表达的影响

Effects of different concentrations of ozone on nigra oxidative stress and apoptosis-related protein expression in rats with Parldnson＇s disease

目的探讨臭氧对帕金森病（PD）大鼠模型黑质氧化应激及凋亡相关蛋白表达的影响。方法SD大鼠32只按随机数字表法分为PD组、20mg／L臭氧治疗组、50mg／L臭氧治疗组和正常对照组，每组8只，前3组大鼠右侧纹状体注射15μg6．羟多巴胺（6-OHDA）制备PD模型，正常对照组注射等量生理盐水；20、50mg／L臭氧治疗组分别在造模后4周经直肠吹入5．0mL氧气和臭氧的混合气体（臭氧浓度分别为20mg／L和50mg／L，剂量为1mg／kg），连续15d。相应处理后取大鼠中脑黑质脑组织，采用化学比色法测定黑质区脂质过氧化产物丙二醛（MDA）、超氧化物歧化酶（SOD）和谷胱甘肽超氧化物酶（GSH-Px）的浓度；采用Westernblotting检测黑质内凋亡相关蛋白B细胞淋巴瘤基因-2（Bcl-2）和Bcl-2相关X蛋白（Bax）的表达。结果与正常对照组比较，PD组和20、50mg／L臭氧治疗组大鼠黑质区GSH-Px活性均降低，MDA含量均增高；与PD组（GSH-Px：6．98±0．60，单位：U／mg·prot；MDA：2．31±0．54，单位：nmoL／mg·prot）比较，20mg／L臭氧治疗组和50mg／L臭氧治疗组大鼠黑质区GSH-Px活性（9．37±0．41、10．04±0．59）升高，MDA含量（1．85±0．29、1．79±0．39）降低，差异均有统计学意义（P〈0．05）。Westernblotting检测结果显示4组大鼠黑质凋亡相关蛋白Bax和Bcl-2的表达比较差异无统计学意义（P〉0．05）。结论臭氧可以通过提高黑质部位GSH-Px活性、降低MDA含量而增强PD大鼠的抗氧化能力，但其对黑质凋亡相关蛋白Bax和Bcl-2的表达无明显影响。

Objective To investigate the effects of different concentrations of ozone on nigra oxidative stress and apoptosis-related protein expression in rats with Parkinson＇s disease （PD）. Methods Thirty-two adult male SD rats aged 2-3 months and weighted 180-220 g were randomly divided into 4 groups （n=8）： PD group, PD＋ozone 20 group （given ozone 20 mg/L）, PD＋ozone 50 group （given ozone 50 mg/L） and control group; rats in the former three groups were given right striatum injection of 15μ g 6-OHDA to induce PD models, and rats in the control group were given the same volume of normal saline; four weeks after PD inducement, mixed gases of 5.0 mL of oxygen and ozone （20 mg/L and 50 mg/L, 1 mg/kg） were given to rats in the PD＋ozone 20 group and PD＋ozone 50 group, respectively, for 15 d. Then, tissues were obtained from nigra; the activities ofsuperoxide dismutase （SOD） and glutathione peroxidase （GSH-Px）, and the content of malondialdehyde （MDA） were measured by using chromometry; the protein expressions of B cell lymphomaJlewkmia-2 （Bcl-2） and Bcl-2 associated X protein （Bax） were detected by using Western blotting. Results As compared with those in the control group, the GSH-Px activity was significantly decreased and the MDA content was significantly increased in PD group, PD＋ozone 20 group and PD＋ozone 50 group （P〈0.05）; the GSH-Pxactivity （6.98±0.60 vs 9.37±0.41 10.04±0.59） was significantly increased and the MDA content（2.31± 0.54 vs 1.85±0.29 、 1.79±0.39） was significantly decreased in PD＋ozone 20 group and PD＋ozone 50 group as compared with those in the PD group （P〈0.05）. Western blotting indicated no significant differences of protein expressions of Bax and Bcl-2 among the four groups （P〉0.05）. Conclusion Ozone can improve antioxidation capability of rats with PD by increasing the activity of GSH-PX, while it does not affect the expression levels of Bax and Bcl-2.