After middle ear infection, the inner ear has been shown to be affected in various ways, such as by endolymphatic hydrops. We studied this relationship biochemically and morphologically in guinea pigs after lipopolysaccharide (LPS) or Staphylococcus aureus was injected into the middle ear.
1. LPS in the inner ear fluids was calculated by the toxicolor test after LPS had been injected into the middle ear. Immediately and 25 minutes later, no statistically significant change of LPS concentration was observed in the inner ear fluids, but in a few cases the concentration was high.
2. One, 3 and 5 days after the middle ear injection of LPS or Staphylococcus aureus, light microscopic studies were performed. The cochleae showed precipitations in the scala tympani and scala vestibuli, but no other outstanding changes were observed in these cochleae and vestibula except that in a few cases after 3 days, there were distended membranes of the sacculus.
After being dipped in cold water, two other guinea pigs were injected in the middle ear with LPS. After 3 days, distended membranes were observed in the sacculi.
3. These results indicate no statietically significa cant changes of LPS concentration in the inner ear after middle ear injection of LPS, but in a few cases the LPS concentration was high and the inner ear seemed to be affected with endolymphatic hydrops.
