Effect of lipopolysaccharide on the permeability of blood labyrinth barrier in guinea pigs / 第三军医大学学报

ABSTRACT

Objective To investigate the change of the permeability of endotoxin-induced blood-labyrinth barrier(BLB) in guinea pigs.Methods Endotoxin was injected into each tympanic cavity of 27 guinea pigs via superior bulla and Evans blue(EB) was injected via jugular vein before sacrification.Another 27 guinea pigs were served as control by injecting normal saline instead of endotoxin.On 12,24,72 h after injection of endotoxin or normal saline,EB content in BLB was detected after the cochlea were immersed in formamide for 24 h and the pathological change of lateral wall was observed by light microscope and transmission electron microscope.Results The BLB permeability to EB increased in endotoxin-induced cochlea of guinea pigs with prolonged time,and the content of EB was significantly different at 24 h in endotoxin-treated cochlea as compared with that at 12 h and 72 h.No marked morphological changes in the stria vascularis and spiral ligament were observed in control group.The pathologic changes in the lateral wall of cochlea in endotoxin-treated group were inflammatory cell infiltration,blood capillary engorgement,intercellular conjunction cleft.Conclusion The BLB permeability can be increased by endotoxin in the cochlea of guinea pigs,which is mainly caused by the capillary interendothelial cleft and continuous break of endothelial cells in stria vascularis.