Function of the eustachian tube after weekly exposure to pepsin/hydrochloric acid.
OBJECTIVE
To determine the effects of repeated pepsin/hydrochloric acid (HCl) exposure on the eustachian tube (ET).


METHODS
ET function was studied in 22 rats. Group I (control) rats received transtympanic phosphate buffered saline solution; groups II (0.5 mg/ml) and III (2.0 mg/ml) received transtympanic pepsin/HCl. Test solutions were applied on day 0 with ET function evaluated on days 1, 2, 3, and 7 after exposure. Each 7-day period represents 1 cycle; all groups underwent 4 cycles. ET function was evaluated using passive opening and closing pressure, and active clearance of positive and negative pressure tests.


RESULTS
Rats exposed to pepsin/HCl had elevated passive opening pressures and a decreased ability to clear positive and negative pressure. A temporal relationship exists.


CONCLUSIONS
The results suggest middle ear exposure to pepsin/HCl leads to ET dysfunction in rats, and that this dysfunction is enhanced with repeated exposures.


CONCLUSIONS
Gastroesophageal reflux may induce ET dysfunction.
Heavner
S B
SB
Department of Surgery, Division of Otolaryngology, Head and Neck Surgery, The University of North Carolina School of Medicine, The University of North Carolina Hospitals, Chapel Hill, USA.
Hardy
S M
SM
White
D R
DR
McQueen
C T
CT
Prazma
J
J
Pillsbury
H C
HC
D000818:Animals; D005064:Eustachian Tube / Q000187:drug effects* / Q000502:physiology*; D005764:Gastroesophageal Reflux / Q000150:complications; D005765:Gastrointestinal Agents / Q000009:adverse effects*; D006851:Hydrochloric Acid / Q000009:adverse effects*; D023421:Models, Animal; D010034:Otitis Media with Effusion / Q000209:etiology; D010434:Pepsin A / Q000009:adverse effects*; D011312:Pressure; D051381:Rats; D017207:Rats, Sprague-Dawley
D005765:Gastrointestinal Agents; D010434:Pepsin A; D006851:Hydrochloric Acid