Action of inflammatory mediators on middle ear mucosa

We describe a technique for measuring changes of permeability and vasodilation-edema in middle ear and Eustachian tube mucosa when this tissue is challenged with an inflammatory mediator. A ten-minute exposure to histamine, bradykinin, and prostaglandin E1 or E2 causes marked increases in permeability and a vasodilation-edema that lasts from 30 minutes to two hours. The passage across the mucosa of a small ion-pertechnetate-is increased by these mediators. Protein molecules, normally prevented from permeating the blood-mucosal barrier, permeate in substantial amounts after the middle ear mucosa is challenged with inflammatory mediators. Thus, the mediators seem capable of producing two of the cardinal signs of middle ear inflammation. They may be the proximal cause of middle ear effusions and their continued presence may be responsible for the chronic nature of this disease.