丹参对低气压噪声暴露豚鼠耳蜗一氧化氮合酶活性的影响

Effects of Salvia Miltiorrhiza and Noise in Hypobaric and Hypoxic Exposure on Expression iNOS in the Cochlea of Guinea Pigs

目的探讨丹参对低压及噪声环境下豚鼠耳蜗诱导型一氧化氮合酶(iNOS)活性的影响。方法豚鼠随机分为暴露1 d 及7 d 两大组,又各分为对照、治疗及防治组。3组均置于模拟高原5 500 m 低气压环境,110 dB SPL 白噪声刺激;防治组和治疗组每日肌注丹参注射液(1.3 ml·kg^(-1))。采用免疫组织化学和图像分析半定量法,观察暴露后不同时间各组耳蜗 iNOS 的表达和阳性产物的平均灰度值。结果正常耳蜗未见 iNOS阳性表达。低压噪声暴露后豚鼠耳蜗外毛细胞、内毛细胞、血管纹及螺旋神经节等部位均可见 iNOS 呈棕黄色颗粒的阳性反应。耳蜗 iNOS 阳性反应各组随暴露时间延长逐渐增强。随出舱后时间延长而逐渐减弱。除暴露1 d 组出舱1 d 的对照组与治疗组的灰度值差异不显著(P>0.05)外,其它各组间差别显著(P<0.05)。暴露7 d 组的防治组、治疗组与对照组、防治组与治疗组间差异非常显著(P<0.01)。结论低压噪声暴露后,豚鼠耳蜗内 iNOS 阳性反应随暴露时间延长逐渐增强,随出舱后时间延长而逐渐减弱;丹参的抗氧化反应.可减轻iNOS 对一氧化氮(NO)的生成.可能为丹参对低压噪声暴露后听器损伤具一定保护功能的机理之一。

Purpose To investigate the effects of salvia mihiorrhiza(SM)and noise in hypobaric and hopoxic exposure on expression iNOS in the cochlea of guinea pigs.Methods Guinea pigs were randomly distributed into 2 groups (exposed 1 and 7 d),each group into 3 subgroups:control group,SM prophylactic treated group and SM treated group.All animals exposed to 110 dB white noise in hypobaric chamber modeling low pressure environment of 5 500 m.The last two groups were injected with SM at the dosage of 1.3 ml·kg-1 per day.Immunohistochemical staining techniques were used (ABC method),and cochleas were observed under light microscopy,examined and analysed by computer image.Results Immunohistochemical studies demonstrated that histological stains of iNOS appeared as golden-brown granules in hair cells, stria vascularis,spiral ganglion after exposure.There was no appoint immunoreactivity in the cochlea of normal guinea pigs. A increasing strong iNOS stain could be observed along with the exposure time.While the stain decreased gradually after exposure in each group.The difference among each groups is significant(P<0.05),especially SM prophylactic treated group was significantly lower than that in control group and treated group after exposure 7 days(P<0.01 ),except 1 day exposed control group with SM treated group.Conclusion A increasing strong expression iNOS could be observed along with the exposure time.While the expression decreased gradually after exposure in each group.SM has certain protective effect on cochlea damage in modeling noise and hypobaric environment.One of the mechanism may be correlated to its effects of anti- freeradical and alleviate NO catalyzed by iNOS.