Vasopressin type-2 receptor mRNA expressions in endolymphatic sac and temporal bone cT findings in Meniere’s disease

Background The temporal bone pathology of Meniere’s disease was proven to be endolymphatic hydrops. However, the mechanisms surrounding hydrops development and symptom onset in Meniere’s disease remain unclear.Aims/Objectives The purpose of this study was to investigate relationships between endolymphatic sac hypoplasia in Meniere’s disease and stress hormone vasopressin type-2 receptor (V2R) mRNA expression in endolymphatic sac.Material and Methods First, we examined temporal bone CT (TBCT) in patients with intractable Meniere’s disease before surgery to evaluate endolymphatic sac hypoplasia. Then, we obtained endolymphatic sac tissues during surgery to examine V2R mRNA expression using real-time PCR.Results All the intractable Meniere’s cases were divided into poorly pneumatized retrolabyrinthine air cells PPR group (n = 9) and non PPR group (n = 3) through the TBCT evaluation. V2R mRNA expression were significantly higher in PPR group (n = 9; 31.78 ± 7.54 fold) than non PPR one (n = 3; 4.22 ± 2.61 fold) through the real-time PCR (Welch’s t-test: t = 3.45; p = 0.0072).Conclusions and Significance Several evidences have suggested that functional dysregulation of inner ear fluid homeostasis is associated with endolymphatic hydrops and Meniere’s disease. Taken together with the present study, it is suggested that coexistence of endolymphatic sac hypoplasia and V2R mRNA overexpression might determine the affected side of endolymphatic hydrops.