目的：探讨乙酸铅对大鼠大脑皮质、小脑、海马组织自由基和脂质过氧化的影响。方法48只刚断乳雄性SD大鼠，按体质量采用随机区组法分为4组（对照组和低、中、高剂量组），对照组大鼠饮用去离子水，低、中、高剂量组分别饮用200、400、800 mg/L的乙酸铅溶液。连续染毒60 d后，取血进行血铅测定，取各组脑组织（大脑皮质、小脑和海马）进行羟自由基抑制活力、过氧化氢（H2O2）水平及丙二醛（MDA）含量的测定。结果与对照组相比，各染铅组大鼠血铅含量显著升高，大脑皮质、小脑和海马组织羟自由基抑制活力明显下降，且随染铅剂量的升高呈逐渐下降趋势（P<0.05）；大脑皮质、小脑和海马组织H2O2水平及MDA含量高于对照组，并随着染铅剂量的升高呈逐渐升高趋势（P<0.05）；大脑皮质、小脑和海马组织的羟自由基抑制活力与血铅含量呈负相关（r分别为-0.505、-0.414、-0.448，P<0.05），H2O2和MDA含量均与血铅含量呈正相关（r分别为0.301、0.411、0.378和0.404、0.324、0.510，P<0.05）。结论铅可通过诱发自由基产生，导致大鼠脑组织发生脂质过氧化反应。%Objective To explore the effects of lead acetate on free radicals and lipid peroxidation in the cerebral cor⁃tex, cerebellum, and hippocampus in rat brains. Methods SD rats (n=48), who were just weaned, were randomly divided in⁃to 4 groups base on their weight. Then the rats were fed with lead acetate in drinking water at the final concentrations of 0 mg/L (deionized water), 200 mg/L, 400 mg/L, 800 mg/L respectively. Blood lead level as well as the hydroxyl free radical inhibiting activity, the levels of hydrogen peroxide (H2O2) and malondialdehyde (MDA) in cerebral cortex, cerebellum, and hippocam⁃pus were measured 60 days after lead contamination in water. Results Upon lead exposure, blood lead levels increased sig⁃nificantly as compared with the control. The hydroxyl free radical inhibiting activity in cerebral cortex, cerebellum, and hip⁃pocampus decreased significantly in a dose dependent manner of lead(P < 0.05). And they all correlated negatively with blood lead level (r=-0.505,-0.414,-0.448, P<0.05). By contrast, blood lead level was positively correlated with H2O2 and MDA in these brain tissues (r=0.301, 0.411, 0.378, and 0.404, 0.324, 0.510,P < 0.05). Conclusion Lead exposure can lead to lipid peroxidation of rat brain tissues through inducing free radicals.
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