Location of intravenously injected kanamycin sulfate in the middle ear mucosa

Twelve guinea pigs were treated with intravenous kanamycin sulfate (KM) and sacrificed 2, 5, 10, and 30 min later to investigate its location in the middle ear mucosa, especially in the Eustachian tube (ET). Immunological examinations evidenced KM in the epithelial and subepithelial layers of the ET on each occasion of observation. But, it was never recognized in the tubal gland. These observations might indicate that clinically used drugs easily get to the ET except for the tubal gland which might have some barrier mechanism against foreign bodies.