铅对大鼠脑组织神经生长因子表达的影响及甲状腺激素的调节作用  

Effect of lead acetate on the nerve growth factor protein expression and the regulation of thyroid hormone

作　　者：张荣[1] 牛玉杰[1] 杨辉[2] 王本华[2] 侯玉春[2] 蔡建宁[1] 张东如[1] 

机构地区：[1]河北医科大学劳动卫生与环境卫生学教研室,石家庄050017 [2]河北医科大学中心实验室,石家庄050017

出　　处：《中华劳动卫生职业病杂志》2003年第6期408-412,共5页Chinese Journal of Industrial Hygiene and Occupational Diseases

摘　　要：目的　研究醋酸铅对大鼠脑组织神经生长因子 (NGF)表达的影响及甲状腺激素的调节作用。方法　对SD大鼠用 2 5、5 0、10 0mg/kg体重的醋酸铅腹腔注射 ;用丙基硫氧嘧啶 (PTU)制作甲状腺机能减退大鼠模型 ,再给予 5 0mg/kg体重的醋酸铅 ,分别以免疫组化测定脑组织中NGF蛋白的表达。以放射免疫方法测定血清中三碘甲状腺原氨酸 (T3 )、甲状腺素 (T4)、促甲状腺激素 (TSH)的含量及脑组织中T3 、T4的含量。结果　中、高剂量组皮层组织NGF平均灰度 (180 .4 9± 10 .33、16 9.72±19 .75 )与对照组 (2 0 0 .75± 3.2 7)相比 ,差异有显著性 (P <0 .0 1) ;各剂量组海马组织NGF面密度 (0 .0 8± 0 .14、0 .12± 0 .0 2、0 .13± 0 .0 4 )与对照组 (0 .0 2 5± 0 .0 15 )相比 ,差异有显著性 (P <0 .0 5 )。甲状腺机能减退后再用醋酸铅处理 ,皮层、海马组织NGF面密度和平均灰度未见明显改变。各剂量染铅组大鼠血清中T3 [(0 .6 8± 0 .0 2 )、(0 .5 7± 0 .0 4 )、(0 .5 4± 0 .0 2 ) μg/L]和T4[(2 8.30± 1.83)、(2 7.35± 2 .5 5 )、(2 4 .0 0± 3.0 1) μg/L]含量明显下降 ,而TSH[(6 .34± 1.13)、(7.74± 0 .79)、(9.16± 0 .77)IU]增高 ,与对照组T3 [(0 .97± 0 .14 ) μg/L]、T4[(5 4 .5 0± 3.70 )Objectives To study the effect of lead acetate on the expression of nerve growth factor(NGF) protein in rat brain and the regulation of thyroid hormone. Methods Lead acetate was given to SD rats intraperitoneally ip.at the dosage of 25,50 and 100 mg/kg respectively.6- n -propyl-2-thiouracil(PTU) was used to make a hypothyroid model and then lead acetate was given at the dosage of 50 mg/kg body weight through ip.The NGF protein expression in rat brain was observed by immunohistoshemistry Triiodothyronine(T_3),thyroxin(T_4),TSH in serum and T_3,T_4 in brain tissue were determined by radio immunoassys(RIAs). Results The average gray value of NGF protein in cerebral cortex of 50 mg,100 mg treated groups(180.49±10.33,169.72±19.75,respectively) were lower than the control(200.75±3.27, P <0.01).The area density of NGF protein in hippocampus of three treated groups(0.08±0.14,0.12±0.02,0.13±0.04,respectively)were significantly different from the control(0.025±0.015, P <0.05).The area density and the average gray value of NGF protein in lead acetate treated hypothyroid rat brain were of no significant changes.The levels of serum T_3 in three treated groups[(0.68±0.02),(0.57±0.04),(0.54±0.02)μg/L respectively] and T_4[(28.30±1.83),(27.35±2.55),(24.00±3.01) μg/L ]in serum were significantly lower while TSH[(6.34±1.13),(7.74±0.79),(9.16±0.77)IU] higher than those in the control[T_3(0.97±0.14)μg/L?T_4(54.50±3.70)μg/L and TSH(4.62±2.16)IU],and there was a good dose-response relationship.The levels of T_3 in cerebral cortex of three treated groups[( 13.26 ±0.81), (11.49 ±0.10),(10.42±1.19)pg/mg pro respectively] and T_4 [(0.50 ±0.03),(0.49±0.13),(0.42± 0.01) ng/mg pro] were significantly lower than those in control[(20.85±11.01)pg/mg pro,(0.76±0.14) ng/mg pro, P < 0.05, P <0.01]. Conclusion Lead could increase the NGF protein expression in rat brain,which may be regulated by thyroid hormone.

关 键 词：铅 大鼠 脑组织 神经生长因子 表达 影响 甲状腺激素 调节作用 

分 类 号：R114[医药卫生—卫生毒理学]