Application of Serratia Marcescans into the Brain of Rats:morphological study / 医学研究杂志

ABSTRACT

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 groupsnamely 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.