铅暴露对生长期大鼠回肠氮能神经元影响  

Effects of lead exposure on nitrergic neurons of ileum in growing rats

作　　者：熊伟[1] 赵英[1] 万炜[1] 雷德亮[2] 伍效琼[2] 孔杏云[3] 

机构地区：[1]南华大学解剖学教研室,湖南衡阳421001 [2]中南大学湘雅医学院人体解剖学和神经生物学系 [3]中南大学公共卫生学院劳动卫生和环境卫生学系

出　　处：《中国公共卫生》2008年第10期1230-1232,共3页Chinese Journal of Public Health

基　　金：国家自然科学基金(30371231)

摘　　要：目的研究铅暴露对生长期大鼠回肠氮能神经元的影响,探讨铅致回肠氮能神经元形态改变或损伤的剂量-效应关系、时间-效应关系,为揭示铅中毒引起腹绞痛的毒理机制提供实验证据。方法6周龄雄性SD大鼠75只,随机分为5组,每组15只,第1,2,3,4组为实验组,第5组为对照组。4个实验组动物分别用15,30,45,90mg/(kg.bw)的醋酸铅,采用灌胃方式染毒,每天1次;对照组以等量的双蒸水灌胃,每天1次。每组大鼠随机分为3小组,每小组以数字加以标注。在第10,30,90 d时对相对应小组大鼠进行血铅测定和回肠壁平铺冰冻块上切片后进行还原型辅酶A(β-NADPH)组织化学染色。结果铅暴露生长期大鼠血铅浓度随染毒时间延长、染毒剂量的加大而升高;回肠一氧化氮合酶(NOS)阳性神经元数量、活性随染毒时间延长、染毒剂量的加大而降低;大鼠血铅浓度与回肠NOS阳性神经元数量存在负性相关,与NOS阳性神经元平均灰度值存在正性相关。结论铅对回肠氮能神经元的影响不仅表现在铅暴露降低NOS活性,而且铅暴露致回肠氮能神经元的数量减少,且存在时间-效应、剂量-效应关系。Objective To investigate the effects of lead exposure on nitrergic neurons of ileum in growing rats in order to provide experimental evidences for revealing the poison mechanism of angina abdominalis in lead poisoning. Methods 75 male sixweek old rats were randomly divided into five groups. There were 15 rats in each group. The rats of four experrnental groups were poisoned by intragastric administration with 15, 30, 45,90 mg/kg lead acetate once a day. The control group rats were intragastricly administered with equal volume double distilled water once a day. Furthermore, rats in each group were stochastically divided into three subgroups, and the subgroups were marked with numbers in turn. On the tenth.30^th,90^th day of the experiment, lead concentration of blood was assayed for the rats in homolgous subgroups. The β - nicotinamide - adenine dinucleotide phosphate（β - NADPH）histochemical method was used to study nitrergic neurons of ileum. Results With extension of lead exposure and the increase of lead dosage, the lead concentration in blood of growing rat increased gradually. However, the number and activity of ileum nitric oxide synthaes （NOS）positive neurons decreased gradually. There were negative correlation between blood lead concentration and the number of NOS positive neurons and positve correlation between blood lead concentration and the average value of gray scale of NOS positive neurons. Conclusion The activity of NOS of nitrergic neurons and the number of nitrergic neurons in ileum decrease with lead exposure and the decrease is influenced by the dosage and time effect of lead exposure.

关 键 词：铅暴露 回肠 氮能神经元 

分 类 号：R183[医药卫生—流行病学]