Regeneration of the damaged endolymphatic sac epithelium.

Abstract

The regeneration of endolymphatic sac (ES) epithelium after epithelial damage was examined using 5-bromo-2'-deoxyuridine (BrdUrd). Guinea pigs and anti-BrdUrd, antikeratin, and anti-basement membrane (BM) component antibodies were used. Animals were sacrificed at 3, 7, and 14 days following an immune injury of the ES. The animals were sacrificed after an administration of BrdUrd at the designated times. Decalcified temporal bones were examined immunohistochemically. At day 3, epithelial loss without subepithelial BM was seen in the region of marked cell infiltration. BrdUrd-positive cells could be detected in the epithelium at the edge of the wound. At day 7, cell infiltration decreased, and the epithelial lining with BM was repaired. These results reveal that the epithelium of the ES can regenerate within 7 days after an immune injury.