L-谷氨酸钠和右美沙芬对锰致大鼠兴奋性神经毒性的影响

Effects of L-glutamicsodium and dextromethorphan on excitoxicity of manganese in rats

目的观察L-谷氨酸钠和右美沙芬(DM)对锰致大鼠神经兴奋性毒性的影响。方法实验用Wistar大鼠24只,按体重随机分成4组,每组6只。第1组为对照组,第2组为单纯染锰组,第3、4组为L-谷氨酸钠和DM预处理组,分别皮下注射L-谷氨酸钠10mmol/kg和DM13.5μmol/kg;2h后,第1组腹腔注射0.9%氯化钠溶液,第2、3、4组腹腔注射200μmol/kg的氯化锰溶液,注射容量均为5ml/kg。连续染锰共25d,L-谷氨酸钠和DM隔日1次皮下注射,共13次,而后测定脑纹状体磷酸活化的谷氨酰胺酶(PAG)和谷氨酰胺合成酶(GS)活力和大脑皮质Na+-K+-ATP酶、Ca2+-ATP酶和琥珀酸脱氢酶(SDH)活力。结果连续染锰后,单纯染锰组大鼠PAG活力明显升高,而GS、Na+-K+-ATPase、Ca2+-ATPase和SDH活力明显下降;DM预处理组与单纯染锰组比较,PAG活力明显下降,而GS、Na+-K+-ATPase、Ca2+-ATPase和SDH活力均明显回升。结论亚急性染锰可使大鼠产生兴奋性神经毒性,并且DM能有效地拮抗锰的这种毒性。

Objective To observe the effects of L-glutamiesedium（L-Glu） and dextromethorphan（DM） on exeitoxieity induced by manganese in rats. Methods 24 Wistar rats were randomly divided into four groups by weight. The first group was the control group and the second one was given only MnCl2. Respectively the third and fourth groups were subcutaneously injected with L-Glu 10 mmol/kg and DM 13.5 μnol/kg every other day. Two hours later, the control group was intraperitoneally given 0. 9% NaCI and the second to fourth groups were given MnCl2 200 μnol/kg. The volume of injection was all 5 ml/kg. 25 days later, the activities of PAG, GS, Na^＋ -K^＋ -ATPase, Ca^2＋ -ATPase and SDH in rat brain were determined. Results The results showed that compared with the control group, PAG activity increased and the activities of GS, Na^ ＋ -K^＋-ATPase, Ca^2＋ -ATPase and SDH decreased significantly in the rats given only MnCl2. Compared with results in the group given only MnCl2, PAG activity decreased and the activities of GS, Na^＋-K^＋-ATPase, Ca^2＋-ATPase and SDH increased significantly in DMgroup. Conclusion Manganese can induce exeitoxieity in rats, and DM can effectively counteract the toxic effects of manganese.