治疗用黏质沙雷菌菌苗大鼠颅内重复给药毒性观察

Application of Serratia Marcescans into the Brain of Rats:morphological study

目的本研究尝试建立一个用小型动物进行颅内重复给药的药理毒性研究方法,并通过观察颅内重复注射治疗用黏质沙雷菌菌苗(雷舒宁、S311)对大鼠大脑的影响及停止给药后的恢复情况,评价雷舒宁颅内重复给药的安全性,为临床使用提供依据。方法用颅内包埋定位导管的方法制备给药动物模型,选择手术埋管成功、健康合格大鼠随机分组后开始给药。雷舒宁给药剂量:低剂量0.32亿/kg、中剂量1.6亿/kg、和高剂量8亿/kg。给药组用微透析仪的微量进样器匀速定点给药,每日给药1次,连续15天。给药前后连续观察动物的一般状况、食量和体重的变化,停药后第25天解剖动物,观察给药后急性期及恢复期大脑的病理学。结果给药期间动物食量和体重都受到一定的影响,并且阴性对照组大鼠食量及体重变化最显著。高剂量组动物脑组织主要病理改变为给药部位周围脑组织、蛛网膜下腔、室管膜的炎细胞浸润,炎细胞主要以胶质细胞、单核、淋巴细胞为主,没有脑组织的变性坏死。给药部位炎性反应与给药剂量有关,中剂量组明显较轻,低剂量组反应不明显。除给药部位周围的炎性反应外,各组动物大脑各皮质的结构是正常的,未发现脑器质性病变。停止给药后25天,给药部位的炎性反应完全吸收。结论建立的大鼠颅内重复给药方法是成功的。雷舒宁颅内给药主要作用于给药部位,引起局限性、可逆性非特异性炎症反应,对其他全身未见明显病理影响。表明该药物颅内重复给药对大鼠是安全的。

Objective To determine the toxicity of therapeutical Serratia marcescans vaccine when repeated intracerebral administration into rat brain. Methods SD rats are prepared by intracranial embedding location catheter and were randomly divided into 8 groups： namely normal control, lunar control group（give NS in same dose） , low dosage group, middle dosage group and high dosage group of acute stage or restore stage. Three dosage of vaccine S311 were administrated （low 320 million/kg, middle 1600 million/kg, high 8000 million/kg）. The embedding catheter rats were fixed point injecting vaccine, once per day for 15 days with microsyringe of microdialysis device. While continuously record the common status, appetite, body weight of animals. 25 days later, Animals were killed to observe the morphology of brain. Results The main pathologic changes of high dosage group were inflammatory cell infiltration into the tissues around injecting location, subarachnoid space, and ependyma. The inflammatory cell is mainly gial cell, monocytes, lymphocytes. No degeneration and necrosis of brain tissue were observed. The inflammatory reaction of brain tissues around injecting location was correlated with the dosages. Except the inflammation around injecting location, the other brain tissues were normal and absent of organic pathological changes. After 25 days restoration, the inflammation around injecting location was absorbed. Conclusions The method of intracranial embedding catheter and fixed point injecting is successful. Intracranial administration of therapeutical Serratia marcescans vaccine is mainly effect on location around injecting to elicit localized, reversible, and non - specific inflammatory reaction.