[Antigen removal after inoculation into the endolymphatic sac of immunized guinea pigs]

Antigen removal in the endolymphatic sac (ES) was immunohistochemically examined. Forty-five adult female Hartley guinea pigs were used in this study. After keyhole limpet hemocyanin (KLH) systemic immunization, KLH was directly injected into the lumen of the right ES. The presence of KLH was detected in histological sections using immunohistochemistry. After KLH challenge into endolymphatic sac lumen, high concentrations of KLH were diffusely found within phagocytes in the endolymphatic lumen and peri-saccular tissue on day 2. After day 14, KLH disappeared from the immunized inner ear. The above results suggest that KLH is removed from the inner ear by diffusion through the endolymphatic epithelial cells which have altered permeability or by phagocytosis of the phagocytic cells. No KLH was observed in the left endolymphatic sac and bilateral cochlea as well as vestibular organ during 5 months of follow up. This study showed that the endolymphatic sac is capable of appropriately trapping macromolecule, KLH antigen (molecular weight: about 400 KDa), and removing antigens quickly from the inner ear.