Luthman J, Olson L, Björklund H, Henschen A, Hoffer B, Oskarsson A
Department of Histology and Neurobiology, Karolinska Institute, Stockholm, Sweden.
Toxicology. 1991 Jan;65(3):333-46. doi: 10.1016/0300-483x(91)90092-f.
Dithiocarbamates are known to form lipid-soluble complexes with lead and greatly increase brain lead levels. The present study was undertaken to investigate whether lead acetate, when administered together with disulfiram (Antabuse, metabolite of dithiocarbamate) during development, would induce morphological changes in brain astrocytes. Female Sprague-Dawley rats were given 0.25% lead acetate in the drinking water from day one of pregnancy and this treatment was continued after birth until the litters were 4 weeks old. In addition, some dams received disulfiram in a dose of 0.1 mmol/kg p.o. twice weekly and after parturition this dose was given s.c. directly to the offspring twice a week. Lead acetate and disulfiram treatments were discontinued at weaning and animals sacrificed 3 weeks later. Samples of parietal cortex, hippocampal formation and cerebellar cortex were dissected out and smeared onto glass-slides and astrocytes were visualized in toto using immunohistochemistry with antibodies against glial fibrillary acid protein (GFA), enabling morphometric analysis with a computerized image analyser. Animals treated with lead acetate showed a minor increase in the size of the GFA-immunoreactive astrocytes in parietal cortex smears, while animals treated with disulfiram showed no difference in size or form compared to controls. However, in combined lead acetate and disulfiram-treated animals a profound increase in astrocyte size and an increase in the number of processes of the individual GFA-immunoreactive astrocytes could be demonstrated in parietal cortex. No significant changes were noted in GFA-immunoreactive astrocytes of hippocampal smears following the different treatments, while GFA-immunoreactive astrocytes in cerebellar cortex smears were significantly smaller and had reduced number or processes following the combined lead acetate and disulfiram treatment compared to lead acetate treatment or controls. It is concluded that combined exposure to lead acetate and disulfiram during development induces regionally specific changes in GFA-immunoreactive astrocyte morphology. Furthermore, the present study demonstrates the usefulness of smear preparations combined with computerized image analysis to study the morphology of GFA-immunoreactive astrocytes as an index of toxic effects in CNS.
已知二硫代氨基甲酸盐能与铅形成脂溶性复合物，并大幅提高脑铅水平。本研究旨在探讨在发育过程中，醋酸铅与双硫仑（二硫代氨基甲酸盐的代谢产物，商品名安塔布司）共同给药时，是否会诱导脑星形胶质细胞发生形态变化。从怀孕第一天起，给雌性斯普拉格 - 道利大鼠饮用含0.25%醋酸铅的水，产后继续此处理直至幼崽4周龄。此外，一些母鼠每周口服两次剂量为0.1 mmol/kg的双硫仑，产后该剂量改为每周两次皮下注射给幼崽。断奶时停止醋酸铅和双硫仑处理，3周后处死动物。取出顶叶皮质、海马结构和小脑皮质的样本，涂抹在载玻片上，使用抗胶质纤维酸性蛋白（GFA）抗体通过免疫组织化学对星形胶质细胞进行整体观察，从而能够使用计算机图像分析仪进行形态计量分析。用醋酸铅处理的动物，顶叶皮质涂片上GFA免疫反应性星形胶质细胞的大小略有增加，而用双硫仑处理的动物与对照组相比，大小和形态无差异。然而，在醋酸铅和双硫仑联合处理的动物中，顶叶皮质可显示出星形胶质细胞大小显著增加，单个GFA免疫反应性星形胶质细胞的突起数量增多。不同处理后，海马涂片的GFA免疫反应性星形胶质细胞未观察到显著变化，而与醋酸铅处理组或对照组相比，醋酸铅和双硫仑联合处理后，小脑皮质涂片的GFA免疫反应性星形胶质细胞明显更小，突起数量减少。研究得出结论，发育过程中联合接触醋酸铅和双硫仑会诱导GFA免疫反应性星形胶质细胞形态发生区域特异性变化。此外，本研究证明了涂片制备结合计算机图像分析在研究GFA免疫反应性星形胶质细胞形态作为中枢神经系统毒性作用指标方面的实用性。
