Objectives: This study determined the preventive effect
of melatonin on the occurrence of experimentally-induced
myringosclerosis of the tympanic membrane (TM).
Materials and Methods: Twenty Wistar albino-type rats
weighing approximately 300 g each were randomly separated
into two groups and myringotomized on the left
TMs: group 1 rats (n=6) received intraperitoneal melatonin
injections 10 mg/kg/day whereas group 2 rats (n=12) were
treated with physiological serum only. The remaining two rats
were served as the control group for histological comparison
and standardization. After 15 days of treatment, myringotomized
membranes were examined by otomicroscopy and
harvested for histopathological evaluation. The functional
effect of myringosclerotic plaques in the TMs of the two
groups were compared with tympanometric measurements.
Results: Tympanic membranes in group 2 revealed extensive
myringosclerotic plaques, on the other hand, TMs in
group 1 showed faint or no existence of myringosclerosis.
The mean magnitude of the maximum admittance from
group 2 measured by tympanometry reduced to about 40%
of the values obtained from group 1 (Z=2,067, p=0.041). The
mean magnitude of the maximum admittance from melatonin
group was very close to the mean tympanometric value of
non-myringotomized Wistar albino rats, demonstrating a
Conclusion: The occurrence of myringosclerosis following
experimental myringotomy can be hindered by systemic
FREE FULL TEXTAnahtar Kelimeler: Deneysel; melatonin; miringoskleroz; timpanogram.