论文部分内容阅读
目的探讨甲基汞对大鼠神经毒性的影响及莱菔硫烷(sulforaphane,SFN)与右美沙芬(dextromethorphan,DM)联合应用的保护作用,为甲基汞中毒的防治提供理论依据。方法选取SPF级Wistar大鼠56只,按体重随机分成4组,每组14只,雌雄各半。其中对照组皮下及腹腔注射生理盐水;低、高剂量甲基汞染毒组皮下注射生理盐水,2 h后分别腹腔注射4、12μmol/kg氯化甲基汞;SFN+DM联合干预组皮下注射5.6μmol/kg SFN和13.5μmol/kg DM,2 h后腹腔注射12μmol/kg氯化甲基汞。每周一、三、五进行预处理,周一至周五染毒,连续4周。染毒结束后24 h分离大鼠脑皮质。采用冷原子吸收法测定大鼠脑皮质内汞含量,流式细胞仪测定细胞内Ca2+浓度、细胞凋亡率和活性氧(ROS)的含量,以试剂盒测定谷氨酸(Glu)、谷胱甘肽(GSH)含量及Na+-K+-ATP酶、Ca2+-ATP酶活力,以Real-time PCR和Western blotting法测定Nrf2、HO-1、γ-GCS、NR1、NR2A和NR2B的m RNA和蛋白表达。结果与对照组比较,低、高剂量染汞组大鼠的脑皮质汞、ROS、Ca2+含量及细胞凋亡率升高,GSH含量降低,Glu含量升高,Na+-K+-ATP酶和Ca2+-ATP酶活力降低,Nrf2、HO-1、γ-GCS m RNA和蛋白表达量升高,NR1、NR2A和NR2B的m RNA和蛋白表达量下降,差异均有统计学意义(P<0.05或P<0.01)。与高剂量染汞组比较,SFN+DM联合干预组大鼠脑皮质汞含量差异无统计学意义(P>0.05),ROS、Ca2+含量及细胞凋亡率降低,GSH含量升高,Glu含量降低,Na+-K+-ATP酶和Ca2+-ATP酶活力升高,HO-1、γ-GCS、NR1、NR2A的m RNA和蛋白表达量升高,差异均有统计学意义(P<0.05或P<0.01)。结论甲基汞可引发大鼠神经毒性,SFN与DM联合应用可有效拮抗甲基汞所致神经毒性。
Objective To investigate the effect of methylmercury on neurotoxicity in rats and the protective effect of combination of sulforaphane (SFN) and dextromethorphan (DM), so as to provide a theoretical basis for the prevention and control of methylmercury poisoning. Methods 56 SPF Wistar rats were randomly divided into 4 groups according to body weight, with 14 mice in each group. The control group received subcutaneous and intraperitoneal injection of normal saline. The rats in the low and high doses of methylmercury injection were injected subcutaneously with normal saline. After 2 h, mice were injected intraperitoneally with methylmercury chloride (4 and 12 μmol / kg) respectively. SFN + DM combined with subcutaneous injection 5.6μmol / kg SFN and 13.5μmol / kg DM, 2μmol / L intraperitoneal injection of 12μmol / kg methylmercury methylmercury. Every Monday, Wednesday and Friday for pretreatment, Monday to Friday, for 4 weeks. Rat cerebral cortex was isolated 24 h after the end of the exposure. The content of mercury in the cerebral cortex of rats was determined by cold atomic absorption spectrometry, the concentration of intracellular Ca2 +, the rate of apoptosis and the content of reactive oxygen species (ROS) were determined by flow cytometry. The contents of glutamic acid (Glu) The content of GSH and the activities of Na + -K + -ATPase and Ca2 + -ATPase were determined by real-time PCR and Western blotting. The m RNA and protein of Nrf2, HO-1, γ-GCS, NR1, NR2A and NR2B expression. Results Compared with the control group, the content of mercury, ROS, Ca2 + and apoptosis in the cortex of rats in the low and high dose groups were decreased, the content of GSH was decreased and the content of Glu was increased. The content of Na + -K + -ATPase and Ca2 + ATPase activity, mRNA and protein expression of Nrf2, HO-1 and γ-GCS were increased, and m RNA and protein expressions of NR1, NR2A and NR2B were decreased, with statistical significance (P <0.05 or P < 0.01). There was no significant difference in the content of mercury in cerebral cortex between SFN plus DM group and high dose mercury group (P> 0.05). The contents of ROS, Ca2 + and apoptosis were decreased, GSH content and Glu content were decreased , The activities of Na + -K + -ATPase and Ca2 + -ATPase were increased, and the mRNA and protein expressions of HO-1, γ-GCS, NR1 and NR2A were significantly increased (P <0.05 or P < 0.01). Conclusion Methylmercury can induce neurotoxicity in rats. Combined application of SFN and DM can effectively inhibit the neurotoxicity induced by methylmercury.