Sıçanlarda deneysel olarak oluşturulan miringosklerozda melatoninin etkisi

Amaç: Bu çalışmada melatonin uygulamasının, timpanik membran TM ’larda deneysel olarak meydana getirilen miringosklerozun oluşumunu engelleyici etkisi araştırıldı.Gereç ve Yöntemler: Herbiri yaklaşık 300 g olan 20 adet Wistar albino cinsi sıçan randomize olarak iki gruba ayrıldı ve sol taraf TM’lerine miringotomi uygulandı: Grup 1 sıçanlara n=6 10 mg/kg/gün intraperitoneal melatonin injeksiyonu yapıldı, grup 2 sıçanlara n=12 ise sadece serum fizyolojik uygulandı. Geriye kalan iki sıçan ise histolojik karşılaştırma ve standardizasyon amacıyla kontrol grubu olarak ayrıldı. On beş günlük tedavi süresinin sonunda miringotomi uygulanan membranlar otomikroskopik olarak incelendi ve histopatolojik inceleme için ayrıldı. Her iki gruptaki miringosklerotik plakların TM’ler üzerine fonksiyonel etkisi timpanometrik ölçümlerle karşılaştırıldı.Bulgular: Grup 2’deki TM’lerde miringosklerotik plaklar yaygın bir şekilde izlenirken, diğer yandan grup 1’deki TM’lerde miringoskleroz ya hafif izlendi ya da hiç izlenmedi. Timpanometrik ölçümler ile grup 2’de elde edilen ortalama maksimum admitans değeri, grup 1’e göre yaklaşık %40 düşük idi Z=–2,067, p=0.041 . Melatonin grubunda ölçülen ortalama maksimum admitans değeri miringotomi uygulanmamış, normal Wistar albino sıçanların standart ortalama timpanometrik değerlerine çok yakındır ve fonksiyonel bir sonuç ifade etmektedir.Sonuç: Deneysel miringotomi sonrasında izlenen miringoskleroz oluşumu sistemik melatonin tedavisi ile engellenebilir

The effect of melatonin on experimentally-induced myringosclerosis in rats

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 functional outcome. Conclusion: The occurrence of myringosclerosis following experimental myringotomy can be hindered by systemic melatonin treatment.

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