| 管燕平,田书心,王碧旭,等.鼻腔路径PM2.5暴露致大鼠中耳炎症及听力损伤的研究[J].浙江中医药大学学报,2022,46(3):264-270. |
| 鼻腔路径PM2.5暴露致大鼠中耳炎症及听力损伤的研究 |
| Study of Middle Ear Inflammation and Hearing Loss in Rats Exposed to PM2.5 via Nasal Route |
| DOI：10.16466/j.issn1005-5509.2022.03.006 |
| 中文关键词: 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 |
| 英文关键词: particulate matter 2.5 hearing impairment inflammatory response nasal route middle ear auditory brainstem response sound-transmit resistance tympanogram |
| 基金项目:国家自然科学基金面上项目(81673672) |
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| 中文摘要: |
| [目的] 探讨鼻腔路径细颗粒物(particulate matter 2.5，PM2.5)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PM2.5染毒组包括第1、3、5、14天处死的亚组。PM2.5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PM2.5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，PM2.5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PM2.5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，PM2.5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。HE染色显示，与正常对照组比较，PM2.5染毒组大鼠染毒后第3、5天中耳黏膜增厚，炎性细胞浸润明显，第5天尤为明显，第14天各指标趋向正常。[结论] 鼻腔路径PM2.5暴露会对大鼠中耳造成急性炎症损伤伴有积液渗出，并引起听力功能下降。 |
| 英文摘要: |
| [Objective] To explore the effect of particulate matter 2.5(PM2.5) 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 PM2.5 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 PM2.5 contamination group included subgroups killed on day 1， 3， 5 and 14 respectively. PM2.5 suspension of 15 mg·mL-1 was injected at the opening of eustachian tube through the middle route of soft palate in PM2.5 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 wave Ⅲ latency 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 PM2.5 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 PM2.5 contamination group decreased significantly on the 3rd and 5th day(P＜0.01， P＜0.0001); and the ABR response thresholds increased significantly(P＜0.01)， and the latency at 40 dB nHL was delayed(P＜0.05， P＜0.001). Compared with normal control group， the expression of IL-6， TNF-α， IFN-γ， MPO， VEGF and MUC5AC increased in MELF of rats in PM2.5 contamination group(P＜0.01)， and the levels of IL-6， IFN-γ， VEGF， MPO and MUC5AC all reached the peak on the 5th day after contamination. HE staining showed that compared with normal control group， the middle ear mucosa of PM2.5 contamination group thickened and inflammatory cell infiltration was obvious on the 3rd and 5th day after exposure， especially on the 5th day， and all indexes tended to be normal on the 14th day. [Conclusion] The exposure of PM2.5 in the nasal route could cause acute inflammatory damage to the middle ear of the rats， accompanied with effusion and exudation， and lead to the decrease of the hearing function of the rats. |
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