摘要
背景:有机磷化合物诱导的迟发性神经毒性发生的确切机制不清楚而尚无有效的治疗方法。目的:观察磷酸三邻甲苯酯对鸡脑组织谷氨酸/谷氨酰胺循环及其关键酶表达的影响。方法:成年罗曼母鸡24只随机分为3组,每组8只。1磷酸三邻甲苯酯染毒组剂量为1 000 mg/kg,经灌胃一次性给予实验鸡。2苯甲基磺酰氟干预组先将苯甲基磺酰氟按40 mg/kg剂量给鸡皮下注射,24 h后,再经灌胃一次性给鸡1 000 mg/kg的磷酸三邻甲苯酯。3对照组则给予等量安慰剂。每组于5 d和21 d时间点各处死4只鸡,迅速取脑于-80℃深冻冰箱保存。ELISA法检测谷氨酰胺合成酶和谷氨酰胺酶含量及谷氨酰胺合成酶活性,应用相应的试剂盒对细胞外谷氨酸和谷氨酰胺浓度进行测定,利用Fluo3-AM检测细胞内钙离子浓度。结果与结论:磷酸三邻甲苯酯在暴露早期(5 d)可诱导鸡脑组织谷氨酰胺合成酶和谷氨酰胺含量及谷氨酰胺合成酶活性显著下降;谷氨酸和细胞内钙离子浓度显著升高。提示谷氨酰胺合成酶活性抑制所导致的谷氨酸/谷氨酰胺循环障碍和钙离子浓度显著升高可能与磷酸三邻甲苯酯暴露鸡诱发的迟发性神经毒性机制密切相关。
BACKGROUND：Although incidents of organophosphate-induced delayed neurotoxicity have been documented for over a century, the molecular mechanisms underlying the axonopathy remain poorly understood. OBJECTIVE：To discuss the effects of tri-ortho-cresyl phosphate （TOCP） on homeostasis of the glutamate-glutamine cycle and the expression of key enzymes in the brains of hens. METHODS：Twenty-four adult hens were randomly divided into three groups （n=8）. TOCP group was treated with TOCP by gavage at a single dosage of 1 000 mg/kg, and control group was given an equivalent volume vehicle by gavage, while hens in the phenylmethylsulfonyl fluoride （PMSF）＋TOCP group were subcutaneously injected with 40 mg/kg PMSF fol owed by 1 000 mg/kg TOCP 24 hours later. The hens were kil ed on days 5 and 21 post-dosing. The brains were taken out quickly and preserved in a-80℃deep freezer. ELISA was used to determination the＆amp;nbsp;content of glutamine synthetase and glutaminase and the activity of glutamine synthetase. Corresponding kits were used to measure the level of glutamate and glutamine. Fluo3-AM was used to measure cytosolic calcium concentration. RESULTS AND CONCLUSION：The activity and content of glutamine synthetase and the concentration of glutamine were down-regulated, while the concentrations of the intracellular Ca2＋and glutamate were up-regulated in the early stage after TOCP administration. It is also suggested that the downregulated expression of glutamine synthetase may be associated with organophosphate-induced delayed neurotoxicity through the disruption of homeostasis of the glutamate-glutamine cycle and cytosolic calcium concentration.
出处
《中国组织工程研究》
CAS
CSCD
2014年第42期6811-6816,共6页
Chinese Journal of Tissue Engineering Research
基金
国家自然科学基金(81102160
30771819)~~
