轻度维生素A缺乏对大鼠肺发育中肺组织血小板源性生长因子A表达的影响

Effect of Mild Vitamin A Deficiency on Expression of Platelet-Derived Growth Factor-A in Lung Development of Rats

目的观察轻度维生素A缺乏(MVAD)对大鼠肺发育中血小板源性生长因子A(PDGF-A)表达的影响。方法 32只清洁级SD大鼠,雌雄各半。雌鼠随机分为MVAD组(n=10)和对照组(n=6)。MVAD组喂养维生素A(VitA)缺乏饲料,对照组喂养正常饲料。3周后雌雄鼠交配,建立MVAD孕鼠模型。高效液相色谱法检测2组雌鼠血清VitA水平和孕20 d胎鼠肝脏VitA水平;测量出生1 d乳鼠身长、尾长、体质量;取MVAD组和对照组出生1 d乳鼠肺组织,反转录(RT)-PCR方法检测出生1 d乳鼠肺脏PDGF-A mRNA的表达,免疫组织化学方法检测其PDGF-A蛋白的表达水平。应用SPSS 13.0软件进行统计学分析。结果 MVAD组雌鼠毛色干枯,少食少动,孕鼠部分流产不孕。MVAD组雌鼠血清VitA水平显著低于对照组(P<0.05)。MVAD组孕20 d胎鼠肝脏VitA水平亦显低于对照组(P<0.05)。MVAD组出生1 d乳鼠身高、尾长及体质量数值均低于对照组(Pa<0.05)。MVAD组出生1 d乳鼠肺组织PDGF-A mRNA表达量显著低于对照组(P<0.05);免疫组织化学检测出生1 d乳鼠肺组织支气管上皮细胞、肺泡上皮细胞、血管内皮细胞内均可见PDGF-A蛋白表达,MVAD组PDGF-A蛋白表达量较对照组少(P<0.05)。结论 VitA在肺发育中起重要作用,MVAD引起PDGF-A的表达减少,可能是大鼠肺发育障碍的原因之一。

Objective To observe the effect of mild vitamin A deficiency（MVAD） on expression of platelet - derived growth factor - A （ PDGF - A） in rat lung development. Methods Totally 32 Sprague - Dawley rats of clean grade were selected ,with 16 cases of male and 16 cases of female. Females were divided into MVAD group（ n = 10） and control group（ n = 6） ,randomly. The rats in MVAD group were fed with fodder of vitamin A （VitA） deficiency, while the rats in control group were fed with fodder of normal VitA sufficient. The rats were mated after 3 weeks of treatment. MVAD models were established in pregnant rats. In both groups, serum VitA content of females and VitA content in liver of 20 d embryos were measured by high performance liquid chromatography, and body weight, body length, tail length of neonatal rats at 1 day after birth were measured. The lungs of neonatal rats at 1 day after birth in MVAD group and control group were obtained. The mRNA and pro- tein levels of PDGF - A gene in lung tissue of neonatal rats at 1 day after birth in MVAD group and control group were detected by the methods of reverse transcription - polymerase chain reaction（ RT - PCR） and immunohistochemistry. SPSS 13.0 software was used to analyze the data. Results It was indicated that the female rats in MVAD group tend to be dry color pattern,less moving and eating activities, and abortion and sterility were also found in some pregnant rats. Compared with control group, serum VitA content of female rats, VitA content in liver of 20 d embryos, and the value of body weight, body length, tail length of neonatal rats at 1 day after birth in MVAD group were lower （ Pa 〈 0.05 ）. RT - PCR results showed that the expression of PDGF - A mRNA in lung tissue of neonatal rats at 1 day after birth was down - regulated in MVAD group compared with that in control group（ P 〈 0. 05 ）. Immunohistochemistry results showed that PDGF - A was expressed in bronchial epithelium, alveolar epithelium and vascular endothelium in lung tissue of neonatal rats at 1 day after birth. The expression of PDGF - A in lung tissue of neonatal rats at 1 day after birth in MVAD group was much lower than that in control group （ P 〈 0.05 ）. Conclusions VitA plays an important role in lung development. MVAD leads to the down - regulated expression of PDGF - A which may be involved in the mechanism of lung hypoplasia.