铅暴露对发育期大鼠肾脏超微结构影响

Affects on ultrastucture of kidney in developmental lead exposed rats

目的:从光镜和电镜水平观察铅暴露对发育期雄性大鼠肾组织的形态学影响。方法:3周龄SD雄性大鼠,随机分为对照组和染铅组。染铅组腹腔注射0.2%乙酸铅溶液(0.2 mL/100 g体质量),隔日1次,共20次,对照组同时注射生理盐水。实验结束后,测量各组动物血铅和血中游离原卟啉,取肾组织作光镜和透射电镜观察。结果:与对照组比较,染铅组血铅含量显著升高,约为对照组的6.2倍;染铅组血中游离原卟啉含量约为对照组的3.6倍;光镜下,染铅组大鼠肾小球肿胀,毛细血管球扩张,肾近曲小管上皮细胞肿胀,肾小管管腔变细,上皮细胞变性,肾间质可见轻度纤维化和炎症细胞浸润;电镜下,染铅组大鼠肾小球系膜细胞内溶酶体增多,足细胞内高尔基复合体体积增大、数量增多,血管球基膜出现沉积性增厚;肾小管上皮细胞核内出现特征性的铅包涵体,并可观察到两种典型铅包涵体结构,有的细胞核内有同心板层样包含物;肾小管上皮细胞内溶酶体增多,出现大量髓样小体和较多的自噬体,胞质内高尔基复合体肿胀、粗面内质网脱颗粒、线粒体出现明显的异型性并有典型的内膜损伤。结论:铅暴露能引起肾组织显著的形态学改变,肾小管上皮细胞核内高电子密度包涵体为铅中毒特征性结构。

Objective： To investigate the morphological changes in kidney of developmental male rats caused by lead exposure from the level of light and electron microscopy.Method： 3-week-old male SD rats were randomly divided into control group and lead group.Rats in lead group were given 0.2% lead acetate solution by intraperitoneal injection（0.2 ml/100g body mass） once every other day,a total of 20,while rats in control group were given normal saline instead.The contents of blood lead and free protoporphyrin of rats in each group were measured at the end of the experiment.The kidneys were taken and observed through light microscope and transmission electron microscope.Results： Compared with control group,blood lead content of rats in lead group was significantly high and 6.2 times more than that in control group,while blood free protoporphyrin content of rats in lead group 3.6 times more than that in control group.Under light microscope,it was observed that glomeruli swelled,glomerulus dilatated and congested,Bowman＇s space narrowed,epithelium cells of proximal convoluted tubule swelled,renal tubules lumen got thinner and epithelium cells degeneratiaon and light degree of fibrosis and inflammatory cell infiltration appeared in renal interstitium.The electron microscope examination showed that glomerular capillary lumen of glomeruli in lead group slightly swelled,the lysosome in mesangial cells of glomerulus increased,Golgi complex in podocytes increased in the size and number and glomerular basement membrane（GBM） got thickening.There were two kinds of characteristic lead inclusion bodies in epithelium cells nuclei of renal tubule.There were some intranuclear concentric laminted inclusions.In epithelial cells of renal tubule,lysosomes increased,a lot of myelin bodies and autophagosomes appeared,Golgi complex swelled and rough endoplasmic reticulum got degranulation,mitochondria heteromorphosis and a typical intimal injury.Conclusion： Lead exposure could cause significant renal morphological changes.High electron density intranuclear inclusions in epithelial nuclei of renal tubular were characteristic ultrastructure of lead poisoning.