Morphological changes in the inner ear induced by bacterial endotoxin
Escherichia coli-derived endotoxin was introduced into the middle ears of 10 guinea pigs 24 hr after intraperitoneal injection of the same endotoxin. The cochleae were removed 24 hr after the introduction of the endotoxin into the middle ears and observed by light and electron microscopy. Inflammatory cell infitration and bleeding were observed in both endolymphatic and perilymphatic spaces. Inflammatory cells also infiltrated the stria vascularis, spiral ligament, spiral prominence and the organ of Corti. Blood sludge was observed in almost all of the strial capillaries of the upper three turns, but in few of the basal turns. The hair cells were intact in every turn except for a small number of degenerated mitochondria. Intermediate cells of the stria vascularis were shrunken, and some of them showed degenerative changes. Marginal cells had also shrunken, but they were less shrunken than the intermediate cells. The shrinking of both cells caused the enlargement of the intercellular space of the stria vascularis.
Key wordsEndotoxin Inner ear Electron microscopy Inflammatory cell Stria vascularis
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