中文摘要：

目的观察2,5-己二酮（2,5-HD）暴露对大鼠坐骨神经组织超微结构及P0（myelin protein zero）和神经丝（neurofilament,NF）表达影响,探讨它们之间的关联性。方法成年雄性SD大鼠40只,随机分成对照组（生理盐水）和低、中、高剂量染毒组（100、200、400 mg/kg腹腔注射2,5-HD）,每组10只,每周连续5 d,1次/d。染毒5周后处死动物,取坐骨神经,电镜观察形态学改变,RT-PCR和Western blot检测P0、NF-L、NF-M和NF-H基因和蛋白表达水平。结果随染毒剂量升高,大鼠坐骨神经髓鞘形状渐不规则,并出现内折现象;轴索形状渐不规则,部分发生萎缩;神经丝数量渐少,排列稀疏。与对照组比较,400 mg/kg 2,5-HD组大鼠坐骨神经P0mRNA表达量（0.75±0.03）、NF-L、NF-M和NF-H mRNA表达量[分别为（0.35±0.07）、（0.25±0.04）、（0.37±0.05）]明显下降（P〈0.05）;与对照组比较,400 mg/kg 2,5-HD组大鼠坐骨神经P0蛋白表达量（0.79±0.04）、NF-L、NF-M和NF-H蛋白表达量[分别为（0.26±0.02）、（0.12±0.03）、（0.22±0.02）]明显降低（P〈0.05）。结论亚慢性2,5-HD暴露导致的外周神经病变可能与P0和NF表达异常有关,这些蛋白可能是2,5-HD攻击外周神经系统的靶点。

英文摘要：

Objective To explore the changes in ultrastructure and the expressions of myelin protein zero（ P0） and neurofilament protein（ NF） in sciatic nerve tissue of rats subchronically exposed to 2,5-hexanedione（ 2,5-HD） and the relationship between the changes. Methods Forty adult male Sprague-Dawley rats were randomly divided into four groups（ 10 in each group） and treated with 2,5-HD saline solution at dose of 0,100,200,and 400 mg /kg by intraperitoneal injection for 5 days a week. After 5 weeks＇ treatment,the rats were executed and the sciatic nerve tissues were divided. M orphological changes in the tissues were observed with electron microscopy. Expressions of P0,NF-L,NF-M and NF-H（ for low,middle,and high molecular weight neurofilament protein） were analyzed with real-time reverse transcription PCR（ RTPCR） and Western blot. Results With the increased exposure,the myelin sheath became irregular in shape and some of them enfolded; the axon also became irregular in shape and some of them appeared atrophy; w hile,the neurofilament decreased in number and arranged scattered. In 400 mg / kg 2,5-HD exposed group,the P0 mRNA expression was 0. 75 ±0. 03 and the NF-L,NF-M,and NF-H mRNA expressions decreased by 0. 35 ± 0. 07,0. 25 ± 0. 04,and 0. 37 ± 0. 05,respectively,w hen compared with those of the control group（ P〈0. 05 for all）. The protein expressions of P0 was 0. 79 ±0. 04,and the NF-L,NF-M,and NF-H protein expressions decreased by 0. 26 ± 0. 02,0. 12 ± 0. 03,and 0. 22 ± 0. 02,respectively（ P〈0. 05 for all）. Conclusion P0 and NFs may be involved in the peripheral nervous damage induced by2,5-HD exposure and they may be the target molecules of the toxincant.