Type 1 Allergy-Induced Endolymphatic Hydrops and the Suppressive Effect of Leukotriene Receptor Antagonist

Objective: To investigate allergic endolymphatic hydrops (EH) and the effect of leukotriene receptor antagonist (LTRA). Methods: Experiment 1: Thirty-six guinea pigs were actively sensitized with DNP-ascaris twice and were provoked with DNP-bovine serum albumin 1 week after the second sensitization. Alterations in the inner ear were investigated histologically at 1, 12, 24, and 36 hours after the provocation, and changes of the endolymphatic space were quantitatively assessed. The animals in the control group received no sensitization but only distilled water. Experiment 2: Twenty-four guinea pigs were actively sensitized and provoked in the same manner. Animals received oral administration of LTRA 1 hour before the provocation. Alterations in the inner ear were investigated as same manner as in Experiment 1. Experiment 3: Eleven of 19 guinea pigs were actively sensitized and provoked in the same manner. Eight animals in the control group received distilled water. One hour after these procedures, the changes in p-AVP levels were investigated. Results: Experiment 1: EH was observed 12, 24, and 36 hours after the last sensitization. In these groups, their cross-sectional areas of the scala media were significantly larger than that of the control group. Degranulation of mast cells was observed in the endolymphatic sac. Experiment 2: In animal groups with LTRA, EH was not observed at all. Experiment 3: P-AVP levels were significantly elevated in animals with the sensitization. Conclusion: The sensitization with DNP-Ascaris produced allergic EH and elevation of p-AVP, and allergic EH was inhibited by LTRA.