Action of histamine on eustachian tube function

INTRODUCTION: The role of allergy in eustachian tube dysfunction is controv ersial. In this study, allergy was simulated by exposure to histamine, and eustachian tube function testing was performed in an experimental rat model . METHODS: Ventilatory function was assessed by measuring passive opening and closing pressures of the eustachian tube after challenge with either trans tympanic or intranasal histamine. The mucociliary clearance time of the tub otympanum was assessed by observing dye transport from the middle ear to th e nasopharynx after challenge with either transtympanic histamine or contro l solution. RESULTS: There was a statistically significant increase in passive opening and closing pressures with transtympanic histamine versus intranasal histam ine. In addition, mucociliary clearance times of the tubotympanum after tra nstympanic histamine showed a statistically significant increase when compa red with those after transtympanic control solution. CONCLUSIONS: Transtympanic histamine exposure causes eustachian tube dysfun ction in the rat by increasing passive opening and closing pressures of the eustachian tube and impairing mucociliary clearance time.