摘要
[目的]探讨鼻腔路径细颗粒物(particulate matter 2.5,PM_(2.5))暴露对SD大鼠中耳黏膜组织学改变和炎症水平的影响,以及与听力损伤的联系。[方法]32只无特定病原体(specific pathogen free,SPF)级健康雄性SD大鼠随机分为8组,正常对照组包括第1、3、5、14天处死的亚组和PM_(2.5)染毒组包括第1、3、5、14天处死的亚组。PM_(2.5)染毒组经软腭正中入路以1 mL·kg-1的剂量于咽鼓管开口处注射15 mg·mL-1的PM_(2.5)悬液,正常对照组注入相同剂量的磷酸盐缓冲液(phosphate buffer solution,PBS)。连续干预7 d,于干预后第1、3、5、14天处死大鼠,进行指标检测。借助电耳镜观察染毒前后大鼠鼓膜形态变化;采用听觉诱发电位仪、声导抗中耳分析仪检测听性脑干诱发电位(auditory brainstem response,ABR)的反应阈值及40 dB nHL声刺激强度下Ⅲ波潜伏期变化、鼓室声导纳值及峰压值变化;酶联免疫吸附试验(enzyme-linked immunosorbent assay,ELISA)检测中耳灌洗液(middle ear lavage fluid,MELF)中血管内皮生长因子(vascular endothelial growth factor,VEGF)、粘蛋白5AC(mucin-5 subtype AC,MUC5AC)、髓过氧化物酶(myeloperoxidase,MPO)和白细胞介素-6(interleukin-6,IL-6)表达水平;采用流式细胞术检测灌洗液中肿瘤坏死因子-α(tumor necrosis factor-α,TNF-α)、γ-干扰素(interferon-γ,IFN-γ)的表达水平;苏木精-伊红(hematoxylin-eosin,HE)染色观察中耳组织切片组织学变化。[结果]与正常对照组比较,PM_(2.5)染毒组大鼠染毒后第3、5天鼓膜表面充血浑浊,少数耳内可见积液。与染毒前比较,染毒后第3、5天PM_(2.5)染毒组大鼠声导纳值和峰压值显著降低(P<0.01,P<0.0001);ABR反应阈值显著升高(P<0.01),40 dB nHL处潜伏期明显延迟(P<0.05,P<0.001)。与正常对照组比较,PM_(2.5)染毒组大鼠MELF中IL-6、TNF-α、IFN-γ、MPO、VEGF、MUC5AC表达升高(P<0.01),其中IL-6、IFN-γ、VEGF、MPO、MUC5AC水平均于染毒后第5天达到高峰。
[Objective]To explore the effect of particulate matter 2.5(PM_(2.5)) exposure in nasal route on histological changes of middle ear mucosa and the level of middle ear inflammatory factor in SD rats,and the relationship between PM_(2.5) exposure and hearing impairment.[Methods]Thirty-two specific pathogen free(SPF)healthy male SD rats were randomly divided into 8 groups,and normal control group included subgroups killed on day 1,3,5 and 14 respectively,and PM_(2.5) contamination group included subgroups killed on day 1,3,5 and 14 respectively.PM_(2.5) suspension of 15 mg·mL-1 was injected at the opening of eustachian tube through the middle route of soft palate in PM_(2.5) contamination group,and the same dose of phosphate buffer solution(PBS)was injected into normal control group.Rats were killed on day 1,3,5 and 14 after 7 days of continuous intervention.Morphological changes of tympanic membrane in rats were observed with otoscope;the threshold of auditory brainstem response(ABR)and the changes of waveⅢlatency under 40 dB nHL stimulation intensity,tympanogram admittance and peak pressure were measured by auditory evoked potential and acoustic immittance middle ear analyzer;the expression levels of vascular endothelial growth factor(VEGF),mucin-5 subtype AC(MUC5AC),myeloperoxidase(MPO)and interleukin-6(IL-6)in the middle ear lavage fluid(MELF)were detected by enzyme-linked immunosorbent assay(ELISA),and the expressions of inflammatory factors tumor necrosis factor-α(TNF-α)and interferon-γ(IFN-γ)in MELF were detected by flow cytometry assay;pathological changes of middle ear tissue sections observed by hematoxylin-eosin(HE)staining.[Results]Compared with normal control group,the surface of tympanic membrane was congested and turbid in PM_(2.5) contamination group,and there was effusion in a few ears on the 3rd and 5th day after exposure.Compared with that before exposure,the acoustic admittance and peak pressure of PM_(2.5) contamination group decreased significantly on the 3rd and 5th day(P<0.01,P<0.0001);
作者
管燕平
田书心
王碧旭
田成华
丁志山
周芳美
GUAN Yanping;TIAN Shuxin;WANG Bixu(Zhejiang Chinese Medical University,Hangzhou(310053),China)
出处
《浙江中医药大学学报》
CAS
2022年第3期264-270,275,共8页
Journal of Zhejiang Chinese Medical University
基金
国家自然科学基金面上项目(81673672)。
关键词
细颗粒物
听力损伤
炎性反应
鼻腔路径
中耳
听性脑干诱发电位
声导抗
鼓室图
particulate matter 2.5
hearing impairment
inflammatory response
nasal route
middle ear
auditory brainstem response
sound-transmit resistance
tympanogram
