三邻甲苯基磷酸酯诱发的迟发陛神经病动物模型的病理和微管相关蛋白的改变

Changes of pathologic feature and microtubulin associated protein 2 in nervous system of hens with organophosphate-induced delayed neuropathy induced by 2, 4, 6-trimethylbenzoyl phenylphosphinate

目的建立母鸡迟发性神经病（OPIDN）模型，观察其病理改变及微管相关蛋白2（MAP2）的改变。方法选取12月龄的产卵母鸡48只，随机分为对照组和3个三邻甲苯基磷酸酯（T0cP）染毒组，每组12只。TOCP染毒组的动物经口一次性灌胃染毒，剂量分别为250、500、750mg／kg，观察中毒症状，染毒后第21天处死动物，其中6只动物取脑、脊髓和坐骨神经，进行HE染色和髓鞘染色；另6只动物的脑组织匀浆后用免疫印迹（Western blot）法测定MAP2的蛋白表达。结果500和750mg／kg剂量组动物出现不同程度共济失调症状，脊髓、坐骨神经出现神经胶质增生、髓鞘脱失及轴突变性。500和750mg／kg剂量组MAP2蛋白表达明显升高，分别较对照组升高了25％和23％，差异有统计学意义（P〈0．05或P〈0．01）。结论TOCP引起各剂量组动物出现不同程度的OPIDN病理改变；TOCP可引起鸡神经组织中的MAP2含量发生改变，这种改变可能与TOCP引起的迟发性神经毒性有关。

Objective To develop the organophosphate-induced delayed neuropathy （OPIDN） hen model with 2,4,6-trimethylbenzoyl phenylphosphinate （TOCP）, and observe the change of pathology and inves- tigate the alterations of microtubulin associated protein 2 （MAP2）. Methods 48 adult hens were randomly di- vided into four groups, including three experimental groups and control group （n=12 each group）.The hens in three experimental groups were treated with TOCP by gavage at single dosages of 250, 500 and 750 mg/kg re： spectively while the control hens received an equivalent volume of corn oil by garage. All hens were sacrificed after 21 days of treatment. Half hens in each group were dissected for HE examination and myelin straining of brain, spinal cord and sciatic nerve while brains of another half hens were dissected for the determination of MAP2 by western blotting. Results The delayed neurotoxicitic symptoms of hens both in 500 and 750 mg/kg groups were consistently observed. The pathological changes of brain, spinal cord and sciatic nerve in 500 and 750 mg/kg groups showed nerve cells diffluence necrosis, increased kytoplasm basophilla, microglia prolifera- tion, mono-nuclear and lymphocyte infiltration, myelin sheath extensive up to part of them disaggregation dele- tion. Compared with the control group, at 500 and 750 mg/kg respectively the increase of MAP2 was 25% and 23% （P〈0.01 and P〈0.05）. Conclusions The histopatholigic changes of OPIDN caused by TOCP have dose- response relationship. The changes of MAP2 in nervous system may contribute to the occurrence and develop- ment of TOCP induced delayed neurotoxicity.