Effects of Balyangtongum-Tang on Cochlear Morphologic Change Induced by Sodium Salicylate Ototoxicity

발양통음탕(發陽通陰湯)이 살리실산나트륨 이독성에 대한 흰쥐 와우의 형태학적 변화에 미치는 영향

Background and Objectives : Despite of high prevalence, Tinnitus remains obscure because the cause and mechanism is poorly understood. In the absence of a suitable animal model, past investigations tool place in humans. Recently, the animal model with sodium salicylate ototoxicity is broadly used because of its reversibility. Balyangtongum-Tang had been used clinically to treat tinnitus and other hearing problems. We investigated the effects of Balyangtongum-Tang on cochlear morphologic change induced by sodium salicylate ototoxicity and were to find out its therapeutic effects on ototoxicity in rat model. Materials and Methods : Healthy ten Sprague-Dawley rats were divided into normal(2), control(4) and sample(4) groups. The sample group was given extract of Balyangtongum - Tang(1cc/100g) once a day for 4 days. After 3 hours when last medication were given, the sample and control groups were injected intraperitoneally with sodium salicylate(500mg/kg). We observed the cochlear morphologic changes of rats every 1, 2, 3 and 5 hours after injection. Results : The electron microscopic finding of outer hair cell shows some changes in the curticular plate and cytoplasm. Some vacuoles were found in the control and sample groups. Vacuolization in the curticular plate and cytoplasm of the sample group after 3, 5 hours were similar to the control group. But the curticular plate of the sample group after 1, 2 hours did not from vacuole. On the other hand the control group after 1, 2 hours formed vacuoles in the curticular plate. Light microscopic findings of cochlear duct in control and sample groups didn't find any difference. Conclusion : The results suggest that extract of Balyangtongum-Tang reduces the morphologic changes induced by sodium salicylate ototoxicity and the effects are remarkable in frist 2 hours. However the effective times are different with previous studies, it seems to due to the difference of tolerance and sensitivity of laboratory animals.