Kim Hee Bok, Lim So Hyun, Cho Chang Gun, Choi Han Seok
Department of Otorhinolaryngology-Head and Neck Surgery, BK21plus, Korea University College of Medicine, Seoul, Korea.
Division of Endocrinology and Metabolism, Department of Internal Medicine, Dongguk University Ilsan Hospital, Dongguk University College of Medicine, Goyang, Korea.
Endocrinol Metab (Seoul). 2018 Jun;33(2):296-304. doi: 10.3803/EnM.2018.33.2.296.
Vitamin D plays an important role in the immune response against infection. The purpose of the present study was to investigate the influence of vitamin D deficiency on the progression of otitis media (OM) using an experimental rat model.
Four-week-old male Sprague-Dawley rats (n=72) were divided into two groups based on their diet: a control diet group (n=36) and a vitamin D-deficient diet group (n=36). After 8 weeks of diet, experimental OM was induced by inoculation of non-typeable Haemophilus influenzae in the middle ear cavity. The rats were evaluated with otomicroscopy to determine the inflammation in the middle ear mucosa on days 1, 2, 4, 7, and 14 post-inoculation. Bullae from sacrificed rats were collected and analyzed histologically.
The middle ear mucosa from rats with vitamin D deficiency showed a significantly higher thickness than that of controls during the course of OM. The maximum mucosal thickness was 56.0±9.1 μm in the vitamin D deficiency group, and 43.9±9.8 μm in the control group, although there was no significant difference in the tympanic membrane score between the two groups evaluated with otomicroscopy. An immunohistochemical study showed increased expression of interleukin 6 (IL-6) and tumor necrosis factor α in rats manifesting vitamin D deficiency and decreased expression of IL-10 compared with controls.
Our results showed that vitamin D deficiency may exacerbate the pathophysiological changes of OM via altered cytokine production. Therefore, maintaining vitamin D status in the optimal range may be beneficial for proper management of OM.
维生素D在抗感染免疫反应中发挥重要作用。本研究的目的是使用实验性大鼠模型探讨维生素D缺乏对中耳炎（OM）进展的影响。
将4周龄雄性Sprague-Dawley大鼠（n = 72）根据饮食分为两组：对照饮食组（n = 36）和维生素D缺乏饮食组（n = 36）。饮食8周后，通过向中耳腔接种不可分型流感嗜血杆菌诱导实验性OM。在接种后第1、2、4、7和14天，用耳显微镜对大鼠进行评估，以确定中耳黏膜的炎症情况。收集处死大鼠的中耳泡并进行组织学分析。
在OM病程中，维生素D缺乏大鼠的中耳黏膜厚度显著高于对照组。维生素D缺乏组的最大黏膜厚度为56.0±9.1μm，对照组为43.9±9.8μm，尽管用耳显微镜评估时两组鼓膜评分无显著差异。免疫组织化学研究显示，与对照组相比，维生素D缺乏大鼠白细胞介素6（IL-6）和肿瘤坏死因子α的表达增加，IL-10的表达降低。
我们的结果表明，维生素D缺乏可能通过改变细胞因子产生而加剧OM的病理生理变化。因此，将维生素D水平维持在最佳范围内可能有利于OM的合理管理。
