Effect of epidermal growth factor and dexamethasone on explosive deafness.
OBJECTIVE
To study the expression of epidermal growth factor receptor (EGFR) on cochlear hair cells of normal and explosion-stricken guinea pigs and the effects of epidermal growth factor (EGF) and dexamethasone (DXM) treatment for blast hearing loss.


METHODS
Immunohistochemical technique and auditory brainstem response (ABR) test were used.


RESULTS
Scattered expression of EGFR was seen in inner hair cells (IHCs) and outer hair cells (OHCs) in normal guinea pigs. Segmentally distributing positive reaction was also located in stereocilia of hair cells. Distribution of EGFR reaction was seen in the cytoplasm of IHC 24 hours after exposure to blasts, and in the stereocilia of IHC and the cuticular plate of OHC 72 hours postexposure. At one week EGFR reaction in hair cells increased obviously and part of OHC stereocilia also showed positive reaction. EGFR reaction reduced at two weeks, though positive reaction could still be found in the stereocilia of hair cells at one month. Combination of EGF and DXM administrations promoted hearing recovery significantly.


CONCLUSIONS
The healing of injured hair cells may be related to EGF.
Wang
J
J
Department of Otorhinolaryngology, Xijing Hospital, Fourth Military Medical University, Xi'an 710032, China.
Jiang
H
H
Liu
S
S
Qiu
J
J
D000818:Animals; D001753:Blast Injuries / Q000150:complications; D003638:Deafness / Q000188:drug therapy* / Q000209:etiology; D003907:Dexamethasone / Q000627:therapeutic use*; D004815:Epidermal Growth Factor / Q000627:therapeutic use*; D066246:ErbB Receptors / Q000378:metabolism*; D005107:Explosions; D006168:Guinea Pigs; D006198:Hair Cells, Auditory / Q000378:metabolism*; D011897:Random Allocation
D004815:Epidermal Growth Factor; D003907:Dexamethasone; D066246:ErbB Receptors