endothelin-1 and Endolymphatic-Hydrops

Endothelin (ET), originally characterized as a 21-residue vasoconstrictor peptide from endothelial cells, has been reported to act as a local hormonal regulator of pressure, fluid, ions, and neurotransduction. Our previous studies suggested an important role of ET-1 in the inner ear. The present study investigated the time kinetics of ET-1 in the epithelium of the endolymphatic sac (ES) of guinea pigs and its relation to the development of endolymphatic hydrops (EH) following locally mounted secondary immune reaction. In the duration between 12 h and day 1, ET-1-like activity completely disappeared from the epithelium of the ES and was associated with the accumulation of inflammatory cells in the ES and a rapid development of EH. On day 7, ET-1-like activity recovered as a consequence of the decrease of inflammatory cells and reduction of EH. These findings suggest that ET-1 may play an important role as one of the regulators maintaining the fluid balance.

Topics: Adjuvants, Immunologic; Animals; Antigens; Endolymphatic Hydrops; Endolymphatic Sac; Endothelin-1; Epithelium; Exudates and Transudates; Female; Freund's Adjuvant; Guinea Pigs; Hemocyanins; Homeostasis; Immunization; Ions; Kinetics; Lymphocytes; Macrophages; Neutrophils; Plasma Cells; Pressure; Synaptic Transmission; Time Factors; Vasoconstrictor Agents