花背蟾蜍肺发生及转化生长因子-β的表达

LUNG HISTOGENESIS AND EXPRESSION OF TGF-β IN BUFO RADDEI STRAUCH

目的分析花背蟾蜍肺发生的规律,观察转化生长因子-β(TGF-β)在肺发育过程中的表达,探讨其生物活性作用及调控意义,为动物学和发育生物学研究提供基础资料。方法利用生物显微技术和免疫组织化学方法,研究花背蟾蜍肺(218只)的组织发生,检测TGF-β(TGF-β1、TGF-2β、TGF-3β)在花背蟾蜍肺组织发生中的表达,并利用IPP专业图像分析软件对其表达强度进行定量分析。结果1.花背蟾蜍的肺发生开始在幼虫第22期,它起始于咽部尾侧,从26期开始分化出微小腔隙,到31期开始形成明显肺腔,33期开始出现原始肺泡,36期肺内出现明显的隔膜和肺泡,肺壁中已有较多毛细血管,39期肺已接近幼蟾肺,肺上皮由矮柱状或立方形变成扁平形。整个发育过程可分为4个阶段,即肺芽Ⅰ期、肺芽Ⅱ期、原始肺泡期和肺泡期。2.在蟾蜍发育早期,TGF-β(β1、β2、β3)在肺壁中有表达,到发育的中后期,TGF-β(1β、β2、β3)主要表达于肺间质细胞处。结论TGF-β(1β、2β、3β)在蝌蚪肺发育过程中的阳性反应呈间歇性变化,表明TGF-β(β1、β2、β3)在花背蟾蜍肺发育的不同阶段具有不同的表达特征,可能发挥着不同的功能,它们对花背蟾蜍肺内网状隔膜的形成,肺泡上皮细胞的成熟分化都有重要的作用。

Objective To analyze the tissue development rule of the Bufo raddei Strauch lung,to observe the expression of transforming growth factor-β（β1,β2,β3 ）in developing lung, and to discuss their functions and relationships. Methods The tissue development of the （218） Bufo raddei Straueh lungs was studied by biological microscope technology,and the expression of TGF-β was measured in lung development by immunohistoehemistry and images were analyzed by IPP, providing a basis for study of the zoology and developmental biology. Results （1） Lung bud oceured in larval 22nd stage from pharynx caudal part. In 26th stage the minutenss locule began to appear. The lung bud gave rise to obvious lung cavity in 31st stage. In 33rd stage originality alveolus began to appear. In 36th stage obvious septum and alveolus appeared. There were many capillary, vessel in the wall of lung. In 39th stage the lung of tadpole was like as one of young toad. The respiratory epithelium differentiated from columnar into squamous. The entire developmental process was divided into four phases,lung bud Ⅰ phase, lung bud Ⅱ phase, originality alveolus phase and alveolus phase. （2）In the early developmental phase, TGF-β expressed in the lung wall. In the late developmental phase,TGF-β expressed in mesenchymal at high levels. Conclusion The expression of TGF-β displayed intermittent changes during the period of development. The functions of TGF-β might be respectively different in different development stages. They not only stimulate the process of epithelium of the reticular septa,but also modulate epithelium of alveolar sac and differention.