铅中毒大鼠肾近曲小管内铅的分布

前人在铅中毒动物肾近曲小管上皮细胞内发现有核内包涵体。这种包涵体曾被认为含有铅.本实验用含铅饲料饲养大鼠一个月后取肾皮质,进行超微结构和X射线显微分析研究。在超薄切片中观察到,肾近曲小管上皮细胞核内有包涵体形成,管腔中可见电子致密斑块。X射线显微分析结果指出,于包涵体的中心区和周边区以及溶酶体和胞质基质中都不产生pb元素峰。只在管腔中的致密斑块中,能产生PbLa峰和CaKa峰。表明致密斑块是铅中毒动物肾内铅沉积部位。而其核内包涵体中并未见铅的沉积,它可能是细胞对铅中毒性作用的反应产物。

DISTRIBUTION OF LEAD IN RENAL PROXIMAL CONVOLUTED TUBULES OF LEAD-POISONING RATS

Intranuclear inclusions were found in epithelial cells of renal proximal convoluted tubules in lead - poisoning animals. It was suggested that the inclusions contained lead. This report presented the results of X-ray microanalysis combined with ultrastructural study of renal cortex samples taken from rats which were fed with laboratory chow containing 2% lead acetate for one month. The X-ray microanalysis showed that both the central part and the peripheral part of the intranuclear inclusions, lysosomes and cytoplasmic matrix gave no lead peak. However, the concretion in the lumen of proximal tubules gave the characteristic La peak of lead (10.551 KeV) and Ka peak of calcium (3.69KeV). From these findings it is suggested thet thei ntranuclear inclusions in cells of renal proximal convoluted tubules are not lead deposits. They may be products of toxic action of lead on cell metabolism. It is the concretion found in the lumen of the tubule that contains lead. It may be an inert chemical form of lead in the lead - poisoning tissues.