研究了苦荞麦多糖对铅中毒小鼠的保护作用及作用机制。采用小鼠每天腹腔注射醋酸铅溶液7 mg/kg，连续注射8 d制备铅中毒模型，自造模第12 d起各组小鼠每天灌胃相应剂量的苦荞麦多糖进行治疗，连续20 d。以避暗实验和Morris水迷宫实验对小鼠进行学习记忆能力和空间辨别能力的测试，采用原子分光光度法分别测定小鼠组织和血浆中的铅含量，采用紫外分光光度法测定组织及血浆中超氧化物歧化酶（Superoxide dismutase, SOD）、谷胱甘肽过氧化物酶（glutathione peroxidase, GSH-Px）活力和丙二醛（malondialdehyde, MDA）含量，采用透射电镜观察铅中毒小鼠海马神经元超微结构。研究发现苦荞麦多糖可显著改善铅中毒小鼠的学习记忆能力和空间辨别能力，显著降低铅中毒小鼠组织和血浆中的铅含量，显著提高铅中毒小鼠组织和血浆中SOD、GSH-Px活力，降低MDA含量，连续20 d灌胃给药苦荞麦多糖可以显著改善铅中毒造成的海马神经元损伤。因此苦荞麦多糖可通过提高铅中毒小鼠抗氧化酶活性，清除自由基，改善铅中毒造成的损伤。

The mechanism and protective effects of Tartary buckwheat polysaccharides (TBP) on lead-poisoned mice were investigated. The mice were injected intraperitoneally with 7 mg/kg lead acetate solution daily, for 8 days to produce the lead-poisoning model. After the model was established, various doses of TBP were administered via gastric infusion by different groups of mice every day from the 12th day on, as treatments for 20 consecutive days. Passive avoidance test and Morris water maze tests were used to test the abilities of learning and memory as well as spatial discrimination, respectively. Lead content in the plasma and tissue were determined by atomic spectrometry. The activities of superoxide dismutase (SOD), glutathione peroxidase (GSH-Px), and the content of malondialdehyde (MDA) in tissues and plasma of the mice were determined using ultraviolet spectrophotometry. Ultrastructure of mice hippocampal neurons was observed by transmission electron microscopy. The results showed that TBP could significantly improve the learning and memory as well as spatial discrimination abilities of lead-poisoned mice and could also significantly reduce lead content in tissues and plasma. The activities of SOD and GSH-Px were significantly increased in the tissues and plasma of lead-poisoned mice, while the content of MDA was decreased. Intragastric administration of TBP for 20 consecutive days significantly improved hippocampus neuronal structure, damaged by lead poisoning. Thus, TBP could repair the damage caused by lead poisoning by enhancing antioxidase activity and scavenging free radicals.

河北省卫生厅医学科学研究重点课题指导项目(20130040)；河北省中医药管理局中医药类科研计划项目（2014203）；河北省自然基金(H2012405016)