大鼠生后锰接触对黑质多巴胺能神经元发育的毒性影响

目的　研究大鼠出生后锰接触对黑质多巴胺 (DA)神经元发育的毒性影响。方法　采用Morris水迷宫试验检测仔鼠的肌力变化 ;荧光分光度计法检测仔鼠尾状核脑匀浆DA含量的变化 ;酪氨酸氢氧化酶(TH)免疫细胞化学 (ABC法 )与图象分析相结合法检测黑质DA神经元和尾状核DA纤维的免疫反应强度和平均相对密度。结果　 (1)随着染锰浓度的增高 ,仔鼠的肌力呈现明显的衰退 ;(2 )尾状核脑匀浆的DA含量 ,随染锰浓度的升高而降低 ;(3)黑质TH免疫反应阳性神经元和尾状核TH免疫反应阳性纤维的反应强度、以及相应的TH阳性产物的平均相对密度 ,均随着染锰浓度的升高而显著下降。结论　大鼠生后锰接触 ,对黑质多巴胺神经元的发育有明显的毒性损害 ,其损害程度随染锰的剂量升高而增加

Toxicity of manganese exposure on the postnatal development of dopaminergic neurons of nigra substance in rat brain

Objective To study the poisonous effect of manganese on the postnatal development of dopaminergic neurons of nigra substance in rat brain. Methods Morris Water Maze was carried out to examine the muscle motor ability of the rat. Fluorometry was used to determine the dopamine levels of caudate nucleus. Immunochemistry combined with digital imagine analysis was carried out to observe the TH reactivity and its average densities of the TH-positive products in nigra substance and caudate nucleus respectively. Results (1)The latency to reach the plateform above water in Morris Water Maze was longer and longer with the increasing of Mn-dose exposured. (2) The DA levels of the caudate nucleus, and the TH-immunochemical reactivity as well as the average densities of TH-positive products in nigra substance and caudate was significantly declined respectively with increasing of Mn-dose exposured. Conclusion The postnatal development of dapaminergic neurons in nigra substance of the rat brain was damaged by manganese-exposured, and the positive relationship existed between the damage effects and the Mn-dose exposured.