制首乌对脑内灌流6-羟基多巴胺所致大鼠纹状体细胞外液羟自由基升高的影响

Effect of Prepared Radix Polygoni Multiflori on the Elevatio n of Extracellular Hydroxyl Radical in Striatum of Rats Induced by Intracerebral Perfusion of 6-hydroxy Dopamine

目的观察制首乌对脑内灌流6-羟基多巴胺(6-OHDA)所致大鼠纹状体细胞外液羟自由基升高的影响,探讨制首乌对脑保护的作用机理。方法用脑内微透析造模,水杨酸捕获羟自由基,高效液相-电化学检测器测定活体脑内羟自由基所形成的2,3二羟基苯甲酸(2,3-DHBA)和2,5二羟基苯甲酸(2,5-DH-BA)。结果6-OHDA脑内灌流后,模型组大鼠纹状体细胞外液2,3-DHBA和2,5-DHBA均迅速增高,前者在观察全程中一直显著高于对照组(P<0.01);后者部分时间点显著高于对照组(P<0.05或P<0.01);制首乌组的2,3-DHBA有5个时点显著低于模型组(P<0.05或P<0.01)。结论制首乌对6-OHDA脑内灌流引起的细胞外液羟自由基升高有一定程度的抑制作用,提示其脑保护作用的机理之一与抗氧化有关。

Objective To investigate the effect and mechanism of prepared Radix Polygoni Multiflori （RPM） on the elevation of extraeellular hydroxyl radical in striatum of rats induced by intraeerebral perfusion of 6-hydroxy dopamine （6-OHDA）. Methods Cerebral mierodialysis was used to establish the model. Hydroxyl radical was captured by salicylic acid, and 2,3-dihydroxy benzyl acid （2,3-DHBA） and 2,5-dihydroxy benzyl acid （2,5-DHBA） formed by hydroxyl radical in vital brain were measured by high performance liquid chromatography-electrochemical detector （HPLC- ED）. Results After perfusion of 6-OHDA in brain of rats, the levels of 2,3-DHBA and 2,5-DHBA in the model group increased rapidly. The former was higher during the whole course of observation （P 〈 0.01 ）, while the latter was higher at most time points than that in the control group （P〈0.05 or P〈0.01）. The level of 2,3-DHBA in the RPM group was lower than that in the model group at 5 time points （P 〈 0.05, P 〈 0.01 ）. Conclusion RPM could inhibit the elevating of extracellular hydroxyl radical in striatum of rats induced by intracerebral perfusion of 6-OHDA, indicating one of the brain protective mechanisms of RPM may be related to its anti-oxidation effect.