【摘要】 [目的]观察不同浓度锰对大鼠脑片神经细胞的损伤情况,探讨诱导型一氧化氮合酶(i NOS)在锰诱导神经细胞损伤中的变化。[方法]培养出生后4~7 d大鼠脑片,培养液为50%高糖杜尔伯科改良伊格尔培养基,25%Hank平衡盐溶液,24%热灭活马血清,1%青霉素和链霉素。待第15天脑片神经细胞生长状态最佳时加入0、25、100、400μmol/L Mn Cl2。培养24 h后,测定培养液中乳酸脱氢酶(LDH)活性,脑片细胞悬液中细胞凋亡率、一氧化氮生成量和i NOS活性,m RNA和蛋白表达水平。[结果]不同浓度锰处理脑片24 h后,脑组织切片神经细胞发生明显损伤。随着锰处理浓度升高,LDH活性升高,100和400μmol/L锰处理组是对照组的1.71、2.76倍。细胞凋亡率和一氧化氮生成量升高增加,25、100和400μmol/L锰处理组分别是对照组的3.31、4.50和6.97倍和1.98、2.79和4.02倍。i NOS活性增强,100和400μmol/L锰处理组分别是对照组的2.12和2.64倍。i NOS m RNA和蛋白表达水平明显升高,25、100和400μmol/L锰处理组i NOS m RNA表达水平是对照组的1.27、1.43和1.86倍。100和400μmol/L锰处理组i NOS蛋白表达水平分别是对照组的4.17和5.50倍。[结论]锰可致大鼠脑片神经细胞一氧化氮生成量和i NOS表达升高,进一步导致细胞凋亡率增加。更多还原

【Abstract】 [Objective] To observe the neurocyte damage in rat brain slices induced by different levels of manganese, and to estimate the effect of inducible nitric monoxide synthase(i NOS) on the neurocyte damage caused by manganese. [Methods] The rat brain slices were prepared and cultured for 15 days with 50% dulbecco’s modified Eagle’s medium, 25% Hank’s balanced salt solution, 24% heat inactivated horse serum, 1% penicillin and streptomycin. Then 0, 25, 100, and 400 μmol/L manganese chloride were added to the rat brain slices culture medium at the 15 th day. After manganese exposure for 24 hours, the lactate dehydrogenase(LDH) activity, neurocyte apoptosis, nitric oxide(NO) content, i NOS activity, i NOS m RNA expression, and i NOS protein expression level were detected. [Results] Explicit neurocyte damage in the brain slice was observed after 24-hour exposure to manganese at varied doses. With the increase of manganese concentration, the LDH activity was increased to 1.71 and 2.76 times of the control group in the 100 and 400 μmol/L groups respectively. The apoptosis rate and NO content were also increased: The apoptosis rates and NO contents in the groups treated with 25, 100 and 400 μmol/L manganese were 3.31, 4.50, 6.97 and 1.98, 2.79, 4.02 times of the control group, respectively. The i NOS activities in the groups treated with 100 and 400 μmol/L manganese were increased to 2.12 and 2.64 times of the control group respectively. The i NOS m RNA and protein expression levels were also increased: The i NOS m RNA expression levels in the groups treated with 25, 100, and 400 μmol/L manganese were 1.27, 1.43, and 1.86 times of the control group; the protein expression levels in the groups treated with 100 and 400 μmol/L manganese were 4.17 and 5.50 times of the control group respectively. [Conclusion] Manganese could result in increases of NO content, as well as i NOS m RNA and protein expression levels in rat brain slices, followed by increase of neurocyte apoptosis rate.更多还原