醋酸铅对大鼠脑皮质区细胞超微结构钙分布和酶活性的影响

用电镜钙细胞化学定位法和酶组织化学亚微数字图像分析系统，观察了断奶ｄ１起，分别给饮用１０和３０ｍｇ·Ｌ－１Ｐｂ２＋水３个月的幼鼠脑组织．发现血铅浓度为对照组１．６５倍时，细胞内钙分布和超微结构无明显变化．血铅浓度为对照组２．４５倍时，脑铅含量增加，Ｃａ２＋－ＡＴＰ酶活性降低，磷脂酶活性增加，钙细胞化学观察见各种细胞的钙分布和超微结构均已发生了变化．结果显示：３０ｍｇ·Ｌ－１的铅染毒量即能引起幼鼠脑皮质区细胞钙代谢的恶性循环，如不给予阻断可能导致细胞进一步损伤．

Effects of lead acetate on the ultrastructural distributionof calcium and enzyme activities in rat brain cortex cells

By using cytochemical technique under electron microscope for detection of calcium and enzyme-histochemical microfigure image analysis system, the calcium distribution and enzyme activities of brain cortex were studied in young rats given Pb 2+ 10 and 30 mg·L -1 in drinking water for 3 months after weaning. It was demonstrated that there were no changes in the intracellular calcium distributions and the ultrastructure of the brain cortex cells when the blood lead level was 1.65 times of that of control, but they were changed when the blood lead level was 2.45 times of that of control. Meanwhile, activity of Ca 2+ -ATPase obviously decreased and that of phosphatidase increased, and brain lead level was higher than that in the control group. The results showed that the exposure of Pb 2+ at 30 mg·L -1 resulted in abnormal calcium metabolism in brain cortex cells of young rats. It is anticipated that if the abnormal calcium metabolism is not interrupted the cellular lesion would be further advanced. The alterations found in the brain cortex cells may be served as useful indicators of early damage induced by exposure to lead.