[Damage caused by endotoxin of the neural components of the organ of Corti].
The endotoxin (lipopolysaccharides, LPS) of H. influenzae extracted with phenol-water method was injected into the perilymphatic compartment of guinea pig via the round window membrane. The CAP thresholds of the cochleas injected with LPS rose to 70.00 +/- 21.76 dB. The N1 latency at threshold prolonged until 2.63 +/- 0.28 ms. Compared with the controls, the differences were significant statistically at the level of 1% and 5% respectively. Electron microscopy found that the neural fibers of the organ of Corti were swollen, organelles degenerated, axon atrophied and disappeared. The myelin sheaths collapsed. The organelles and vesicles in the synapses decreased and disappeared. The synaptic membrane destroyed. The results exhibited that the LPS of H. influenzae had toxic effects on the neural components of the organ of Corti and the degeneration of the neural components was the pathological basis of the elevation of CAP thresholds and the N1 latency delay. It is concluded that once endotoxin enters into the perilymphatic compartment, it not only causes physiological changes but results in irreversible alterations of the neural components pathologically.
Lin
J Z
JZ
D000200:Action Potentials / Q000187:drug effects; D000818:Animals; D015834:Cochlear Diseases / Q000139:chemically induced / Q000473:pathology* / Q000503:physiopathology; D004731:Endotoxins; D005260:Female; D006168:Guinea Pigs; D006193:Haemophilus influenzae; D008297:Male; D009925:Organ of Corti / Q000648:ultrastructure*
D004731:Endotoxins