维生素D对大鼠哮喘模型气道炎症的影响

Vitamin D exacerbates airway inflammation in asthmatic rats

目的通过在大鼠出生后早期补充维生素D[1,25(OH)_2D_3],研究其对大鼠哮喘模型气道炎症的影响。方法将出生后早期(相当于人类婴儿时期)的Wistar大鼠分为维生素D高剂量组(10μg/kg)、维生素D低剂量组(5μg/kg)和对照组,分别给予相应剂量的维生素D进行干预。同时用卵清蛋白致敏和激发,建立哮喘动物模型。收集支气管肺泡灌洗液(BALF)进行细胞计数;取肺组织石蜡包埋切片,观察气道炎症情况。结果维生素D高剂量组的BALF中细胞总数及嗜酸性粒细胞百分比均明显高于维生素D低剂量组和对照组(P值均<0.05),维生素D低剂量组又明显高于对照组(P值均<0.05)。维生素D高剂量组的肺部病理改变程度较维生素D低剂量组更为严重,对照组的肺部病理改变程度较维生素D高剂量组和低剂量组为轻。结论出生后早期维生素D促进哮喘的发生,加重气道炎症病变程度,高剂量的作用更加明显。

Objective To explore the effect of vitamine D[1, 25（OH）2D3] on airway inflammation in weaning rats with asthma. Methods Eighteen 21-day-old Wistar rats were divided equally into a control, high-dose and low-dose vitamin D groups, and in the latter two groups, vitamin D at 10 and 5μg/kg was administered intraperitoneally. On days 6 and 13, the rats were sensitized with ovalbumin via introperitoneal injection and challenged with daily ovalbumin inhalation for 5 consecutive days since day 20. After the challenge, the bronchial alveolar lavage fluid（BALF） was collected for examining the total cell number and eosinophil count, and the lung tissue was taken to evaluate the airway inflammation. Results The total BALF cell count and eosinophil percentage were the highest in the high-dose vitamin D group, followed by the low-dose group and the control group（P〈0.05）. More serious pathological changes were found in the lung tissues of rats given high-dose vitamin D than in the low-dose group, and asthmatic airway inflammation was the slightest in the control group. Conclusions Vitamin D administered early after birth, especially at high doses, may give rise to more frequent asthmatic attack and aggravates airway inflammation in asthmatic rats.