LUNG HISTOGENESIS AND EXPRESSION OF TGF-? IN BUFO RADDEI STRAUCH / 解剖学报

ABSTRACT

Objective To analyze the tissue development rule of the Bufo raddei Strauch lung,to observe the expression of transforming growth factor-?(?_1,?_2,?_3)in developing lung,and to discuss their functions and relationships. Methods The tissue development of the(218) Bufo raddei Strauch lungs was studied by biological microscope technology,and the expression of TGF-? was measured in lung development by immunohistochemistry and images were analyzed by IPP,providing a basis for study of the zoology and developmental biology. Results(1) Lung bud occured 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 Ⅰphase,lung bud II phase,originality alveolus phase and alveolus phase.(2)In the early developmental phase,TGF-? expressed in the lung wall.In the late developmental phase,TGF-? expressed in mesenchymal at high levels.Conclusion The expression of TGF-? displayed intermittent changes during the period of development.The functions of TGF-? 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.