Article Type

Original Study


The main target of the present work is to study the ultrastructure and expression of cytokeratin 13' 16{CK13/16), as a marker of ceil pro­liferation, of tympanic membrane (TM) of normal guinea pigs and after Eus-tachian tube (ET) obstruction. The present study was conducted on 24 healthy guinea pigs. The right ET na-sopharyngeai orifice of all animals was obstructed by electrocauterlza-tion while the contraiaterat left ear served as controls. The animais were classified into three equai croups ac­cording to the time interval following ET obstruction either after two, four or eight weeks. The TMs of 12 animals were stained immunohistochemically for detection of CK13/16 and that or other 12 animals were subjected for electron microscopic study. The re- suits showed that the pars tensa of control group is formed of outer epi­thelial layer, lamina propria and inner rnucosal layer. Obstruction of ET led to inflammatory changes in the form of hemorrhage and infilteration of the subepithelial and submucosal layers of the lamina propria with inflamma­tory cells. After eight weeks of ET obstruction, the epithelium showed increase thickness and hype rpro life ra­tion as detected by increase the ex­pression CK13/16 that was not re­stricted to the basa! cell layer but found in many suprabasal layer. Also, the dense network of collagen fibers found in the normal TM was de­stroyed with few fibers remaining. From the present work it can be con­cluded that the patency of ET is es­sential for the integrity of TM. Also, the increase of CK 13/16 pattern and

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Creative Commons Attribution 4.0 International License
This work is licensed under a Creative Commons Attribution 4.0 International License.