牛磺酸对染锰所致大鼠丘脑氨基酸类神经递质改变的干预作用

TAURINE TREATMENT INTERVENTS THE TRANSFORMATION OF AMINO ACID NEUROTRANSMITTERS IN THALAMUS OF MANGANESE-EXPOSED RATS

目的:探讨牛磺酸对染锰所致大鼠丘脑氨基酸类神经递质改变的干预作用。方法:按随机方法将SD大鼠分为空白对照组、染锰组、预防组、治疗组和治疗对照组,共5组。染锰组、预防组、治疗组和治疗对照组大鼠腹腔注射MnCl2.4H2O20mg/kg·d-1,其中预防组大鼠同时腹腔注射牛磺酸200mg/kg·d-1,空白对照组腹腔注射等容量生理盐水,连续8周,每周5d,染锰组、预防组和空白对照组试验终止。然后,治疗组大鼠继续腹腔注射牛磺酸200mg/kg·d-1,治疗对照组大鼠腹腔注射等容量生理盐水,连续8周。最后一次注射后24h处死大鼠,切取丘脑。用BCA蛋白浓度测定试剂盒测定样品中的蛋白含量,用高效液相色谱(HPLC)紫外检测法测定大鼠脑丘脑谷氨酸(glutamic acid,Glu)、谷氨酰胺(glutamine,Gln)和γ-氨基丁酸(gamma-aminobutyric acid,GABA)的含量。结果:染锰8周后,染锰组Glu含量比空白对照组含量高,差异有统计学意义(P<0.05);染锰组Gln和GABA含量比空白对照组低,差异有统计学意义(P<0.05)。牛磺酸预防8周时,预防组Glu含量比染锰组含量低,差异有统计学意义(P<0.05);预防组Gln和GABA含量比染锰组高,差异有统计学意义(P<0.05)。牛磺酸治疗8周后,治疗组Glu含量均比治疗对照组含量低,治疗组Gln和GABA含量均比治疗对照组含量高,差异有统计学意义(P<0.05)。结论:锰可致大鼠丘脑Glu升高,Gln和GABA减低,牛磺酸对锰所致大鼠丘脑Glu、Gln和GABA的改变有干预作用。

Objective： To explore the effects of taurine on amino acid neurotransmitters in thalamus of manganese-exposed rats. Methods： Male Sprague Dawley rats were randomly divided into 5 groups. The rats in manganese chloride, prevent, treated, and control groups were injected i. p. with MnCl2 · 4H2O 20 mg/kg · d 1 and the rats in blank group were injected with saline 5 d/week for 8 weeks. At the same time, the rats in prevent group were injected with taurine 200 mg/kg · d 1. And then, the rats in treated group were injected with taurine 200 mg/kg · d-1 and the rats in control group were injected with saline 5 d/week for 8 weeks. Twenty-four hours after the last injection, the rats were executed and the thalamus was cut off. Protein concentrations in the thalamus were determined using a BCA protein assay kit, and the concentrations of glutamic acid （Glu）, glutamine （Gin） and gamma-aminobutyric acid （GABA） in the thalamus were detected by the high performance liquid chromatography （HPLC） ultraviolet detection technique. Results： After 8 weeks of manganese treatment, the manganese chloride group had higher Glu concentration than the blank group （ P 〈0.05） and the blank group had higher concentration of Gln and GABA than the manganese chloride group （P 〈 0.05）. After 8 weeks of taurine prevention, the manganese chloride group had higher Glu concentration than the prevent group （ P 〈0.05） and the prevent group had higher concentration of Gin and GABA than the manganese chloride group （ P 〈0.05）. After 8 weeks of taurine treatment, the control group had higher Glu concentration than the treated group （ P 〈0.05） and the treated group had higher concentration of Gln and GABA than the control group （ P 〈0.05）. Conclusion： The neurotransmitter levels of Glu are increased and the neurotransmitters levels of Gln and GABA are decreased in thalamus of rats by the manganese exposure. The taurine has the intervention effect to the transformation of Glu, Gin and GABA neurtrosis in thalamus of manganese-exposed rats.