Auditory epithelial migration. II: Morphological evidence for auditory epidermal cell migration in rat.
Morphology of the tympanic membrane (TM) and external auditory canal (EAC) was studied in healthy, intact rat ears. TM-perforated ears (3 days after making the perforation) and TM-perforation-healed ears (14, 28 and 42 days after making the perforation). In intact ears, the epidermis in the annular region of the EAC displayed a characteristic appearance with cytoplasmic protrusions. We termed these protrusions as "finger-like projections". In contrast to the rat, the annular region of the EAC in the guinea-pig did not show "finger-like projections". Following a perforation in the centre of the anterior or the posterior quadrant of the pars tensa in rats the "finger-like projections" disappeared from the annular region on the perforated side of the EAC, while the projections remained on the malleus side of the perforation edge. In perforation-healed ears analysed 42 days after the perforation, the "finger-like projections" had recurred in the annular region on the perforated side of the EAC. The "finger-like projections" are likely to express maturation (keratinization) and desquamation of epidermal cells in the pars tensa and also could constitute morphological evidence of their migration on the TM.
Kakoi
H
H
Department of Otorhinolaryngology and Head & Neck Surgery, University Hospital (Akademiska sjukhuset), Uppsala, Sweden.
Anniko
M
M
D000818:Animals; D002465:Cell Movement; D004431:Ear, External / Q000648:ultrastructure*; D004848:Epithelium / Q000648:ultrastructure; D006168:Guinea Pigs; D051381:Rats; D017207:Rats, Sprague-Dawley; D014432:Tympanic Membrane / Q000502:physiology / Q000503:physiopathology / Q000648:ultrastructure; D018058:Tympanic Membrane Perforation / Q000503:physiopathology; D014945:Wound Healing