Experimental design
The study was designed to have the right ears of the rats as the control group and the left ears as the experiment group.
Propylene glycol was used to form cholesteatoma and inflammatory reaction in the middle ear mucosa. Mesna was used to inhibit the pathologic processes in the middle ear mucosa and gentamicin to inhibit the inflammatory process of sulfate. Intratympanic injections were administered to all rats on the pars tensa region of the tympanic membrane on days 1, 3, 8, 15 and 21 under surgical microscope. Each ear had 5 administrations in total. The rats were sacrificed 45 days after the first injection.
Solutions used in the control group (right ear): 0.2 ml %50 propylene glycol, 0.1 ml gentamicinsulfate (40 mg/ ml) and 0.1 ml physiologic salt water (%0.9).
Solutions used in the experimental group (left ear): 0.2 ml %50 propylene glycol, 0.1 ml gentamicinsulfate (40 mg/ ml) and 0.1 ml %20 Mesna (100mg/ ml).