罗布麻宁减轻D-半乳糖诱导的老化大鼠听皮层线粒体氧化损伤  

Apocynin Decreases Mitochondrial Oxidative Damage in Auditory Cortex in D-galactose-induced Aging Rats

作　　者：杜政德 熊伟[1] 于树夔 柳柯[1] 龚树生[1] DU Zhengde;XIONG Wei;YU Shukui;LIU Ke;GONG Shusheng(Department of Otorhinolaryngology,Beijing Friendship Hospital,Capital Medical University,Beijing 100050,China)

机构地区：[1]首都医科大学附属北京友谊医院耳鼻咽喉科,北京100050

出　　处：《中华耳科学杂志》2019年第2期243-247,共5页Chinese Journal of Otology

基　　金：国家自然科学基金青年基金(81700917);中国博士后科学基金面上资助一等资助(2018M630180);深圳市科创委基础研究项目(JCYJ20160429181957912);深圳市南山区重点科技计划(2016004)~~

摘　　要：目的研究NADPH氧化酶抑制剂罗布麻宁(Apocynin, APO)对D-半乳糖诱导的老化大鼠听皮层线粒体氧化损伤的作用。方法 36只1月龄雄性Sprague-Dawley大鼠适应性喂养1周后随机分为3组(每组12只):①对照组:大鼠颈背部皮下注射生理盐水,每日1次,连续8周;②D-半乳糖组:大鼠颈背部皮下注射500mg/kg D-半乳糖,每日1次,连续8周;③D-半乳糖+罗布麻宁组:大鼠颈背部皮下注射500mg/kg D-半乳糖+腹膜内注射50mg/kg罗布麻宁,每日1次,连续8周。我们利用酶化学法检测H2O2、总超氧化物歧化酶(Total superoxide dismutase, T-SOD)活性、ATP和线粒体膜电位水平,利用免疫组织化学法检测DNA氧化损伤标记物8-羟基-2-脱氧鸟苷(8-hy?droxy-2-deoxyguanosine, 8-OHdG),利用透射电子显微镜观察听皮层线粒体超微结构。结果和对照组相比较,D-半乳糖组大鼠听皮层H2O2和8-OHdG水平显著增加,而T-SOD活性、ATP和线粒体膜电位水平则显著降低。和D-半乳糖组相比较,D-半乳糖+罗布麻宁组大鼠听皮层H2O2和8-OHdG水平显著降低,而T-SOD活性、ATP和线粒体膜电位水平则显著增加。同时,我们也观察到罗布麻宁可有效保护D-半乳糖诱导的老化大鼠听皮层线粒体超微结构。结论罗布麻宁可有效保护中枢听觉系统老化过程中线粒体氧化损伤。Objective To investigate the effects of apocynin (APO), an NADPH oxidase inhibitor, on mitochondrial oxidative damage in the auditory cortex of D-gal-induced aging rats. Methods After acclimation for a week, 36 one-month-old male Sprague-Dawley rats were randomly allocated into three groups (n=12 per group):① Control group: rats were injected subcutaneously with 0.9% saline once a day for 8 weeks;② D-gal group: rats were injected subcutaneously with 500 mg/kg D-gal once a day for 8 weeks;③ D-gal+APO group: rats were injected subcutaneously with 500 mg/kg D-gal and intraperitoneally with 50 mg/kg APO once a day for 8 weeks. The levels of H2O2, total superoxide dismutase (T-SOD) activity, ATP and mitochondrial membrane potential (MMP) in the auditory cortex were tested by enzymatic chemistry. The level of 8-hydroxy-2-deoxyguanosine (8-OHdG), a biomarker of DNA oxidative damage, in the auditory cortex was analyzed by immunohistochemical methods. The ultrastructure of mitochondria in the auditory cortex was examined by transmission electron microscopy. Results Compared with the control group, the levels of H2O2 and 8-OHdG in the auditory cortex were significantly increased in the D-gal group, while the levels of T-SOD activity, ATP and MMP were significantly decreased. Compared with the D-gal group, the levels of H2O2 and 8-OHdG in the auditory cortex were significantly decreased in the D-gal+APO group, while the levels of T-SOD activity, ATP and MMP were significantly increased. APO also appeared to protect mitochondrial ultrastructure in auditory cortex in D-gal-induced aging rats. Conclusion Our findings suggest that protection of mitochondrial structure and function by APO is a potentially effective method to enhance central auditory neuronal resistance to aging.

关 键 词：老年性聋 听皮层 线粒体氧化损伤 罗布麻宁 D-半乳糖 

分 类 号：R764[医药卫生—耳鼻咽喉科]