雄黄亚慢性染毒对未成年大鼠脑组织内Glu和Gln水平的影响

Effect of Subchronic Realgar Exposure on Glu and Gln in Infant Rat Brain

目的:通过研究雄黄对大鼠脑组织中Glu和Gln水平的影响,探讨雄黄对大鼠神经系统的毒性。方法:将48只Wistar大鼠随机分为对照组(0.5%CMC)及雄黄低(0.3 g/kg)、中(0.9 g/kg)、高(2.7 g/kg)剂量染毒组,连续灌胃给予雄黄混悬液6 w。采用氢化物发生-冷阱捕集-原子吸收法测定脑组织中无机砷(iAs)、一甲基胂(MMA)、二甲基胂(DMA)含量,高效液相色谱法测定脑组织中Glu和Gln含量。结果:雄黄染毒组大鼠脑组织中MMA、DMA含量随染毒剂量增加而增加,二甲基化率(SMI)降低。与对照组比较,雄黄染毒组大鼠脑组织中Glu含量显著降低(P<0.05);Gln含量也有降低趋势,其中低剂量组与对照组比降低有统计学差异。结论:雄黄染毒后可引起MMA、DMA在大鼠脑组织中蓄积,SMI水平降低,脑组织中Glu和Gln含量减少。

Objective：To study the effect of realgar on Glu and Gln on rat brain tissues. Methods：Forty-eight Wistar rats were di- vided into 4 groups randomly：control group,low dosage group, moderate dosage group and high dosage group. The treatment groups were treated with realgar by gastric perfusion at a dosage of 0. 3 g/kg,0. 9 g/kg,2. 7 g/kg and the control group ones were orally given the same volume of 0. 5% sodium carboxymethylcellulose （CMC-Na） for 6 weeks. The contents of inorganic arsenic, monomethylarsonic acid（MMA） and dimethylarsinic acid （DMA） in brain tissues were measured by hydride generation-atomic absorption （HG-AAS） method. The contents of amino acid in brain tissues of rats were determined by means of high performance liquid chro- matography with precolumn derivatization. Results：The levels of MMA and DMA in brain increased as the dosage of realgar increased, while the second methylation index declined. Compared with control group, the levels of Glu was significantly decreased in realgar trea- ted group （ P 〈 0. 05 ） ; Gin also tended to decrease and that of low dosage group was obviously decreased compared with controls. Conclusion：Realgar exposure can cause accumulation of MMA and DMA, declination of second methylation index and there- duction of Glu and Gln in brain tissue.