镉对慢性镉中毒小鼠黑质神经元的损害及维生素C的拮抗作用

目的研究维生素C（VC）对慢性镉中毒小鼠黑质神经元的保护作用。方法将75只雄性昆明种小鼠随机分为3组，每组25只。镉中毒组皮下注射氯化镉（CdCI：），每周2次，每次2mg／kg，VC加镉组（VC组）上述方法和剂量染镉外，VC按每次25mg稀释后灌胃，正常组同时给予生理盐水。3个月后对小鼠进行Y型迷宫学习能力检测，并通过光镜及透射电镜观察小鼠黑质神经元的细微结构。结果Y型迷宫检测显示，VC组与镉中毒组相比，小鼠的学习、记忆能力均降低，差异有统计学意义（P〈0．05）；与正常组比较，差异无统计学意义（P〉0．05）。光镜和电镜结果显示，VC组小鼠中脑黑质区结构接近正常组，与镉中毒组比较有明显差异。结论抗氧化剂VC对慢性镉中毒组小鼠黑质神经元有显著的保护作用。

Impairment on neurous of substantia nigra in chronic cadmium poisoning mice and antioxidation effects of vitamin C

Objective To investigate the protective effects of vitamin C on the neurons of substantia nigra in chronic cadmium poisoning mice. Methods Totally 75 male Kunming mice were randomly divided into three groups ： cadmium poisoning-exposed group （ Cd-exposed group）, vitamin C treatment group and control group （n = 25）. Cd-exposed group was given CdCI2 （2 mg/kg each time） subcutaneously and semiweekly （2 mg/kg each time）. Vitamin C treatment group was given CdC12 simultaneously and semiweekly （2 mg/kg each time）, meanwhile vitamin C was administered perorally everyday （25 mg each time）. Control group was only given equival physiological saline subcutaneously. The learning and memory abilities were detected by Y-maze after three months of treatment. Then the microstructure of the substantia nigra was observed under light microscopy and transmisson electronicm icroscopy. Results According to the results of Y-maze test, the learning and memory capacity in vitamin C treatment group were lower than those in Cd-exposed group （ P 〈 0.05 ） and there was no difference compared with those in control group （ P 〉 0.05 ）. The microstructure of the substantia nigra in vitamin C treatment group was similar to that in control group, but it was obviously different from that in Cd-exposed group. Conclusion The antioxidants of vitamin C could efficiently protect the neurons of substantia nigra in chronic cadmium poisoning mice.