Endocrine cells have been observed from 13 cases of human fetal lungs through the using of Grimelius silver staining technique, fluorescence microscopy and ultrastructural examinations. They were found in great number in the small bronchi than in any other part of bronchial tree. Most of them were round or oval in shape, and usually rest on the basement membrane of epithelium. They were stained by Grimelius silver stain. After incubation with L-Dopa they emitted a green glyoxylic acid-induced fluorescence. Typical feature of these cells was the numerous electron dense neurosecretory-type granules, 168-312 nm in diameter, which can be seen throughout the cytoplasm.

Purpose　To study the effect of heparin on expression of type collagen Ⅰ,ⅢmRNA in cultured fetal rat lung fibroblast (LFb). Methods　By using Northern blot method and immage analysis,the expression of collagenⅠ, Ⅲ mRNA were quantitatively analysed in the fibroblasts treated with different concentration heparin (0.1 mg/L, 1 mg/L, 10 mg/L, 100 mg/L)separately. Results　Heparin treatment at 0.1 mg/L,1 mg/L, 10 mg/L and did not influence the expression of collagen Ⅰ,Ⅲ mRNA，but the expression of collagen Ⅰ,Ⅲ mRNA were inhibited at 100 mg/L. Conclusion　Expression of collagen Ⅰ, ⅢmRNA is related to the concentration of heparin.

To study the expression of transforming growth factor β1 (TGFβ1) and platelet-derived growth factor (PDGF) in alveolar type Ⅱ cells and their significance in the process of pulmonary fibrosis. MethodsCultivation of alveolar type Ⅱ cells were mode from normal adult rat and of silicotic animal model of rat was established. In situ hybridization and irnmunohistochemieal staining were applied to detect the gene expression of TGFβ1 and PDGF-B in the alveolar type Ⅱ cells of primary culture and silicotic tissue. Results(1) In situ hybridization and immunohistochemical staining showed the positive expression of TGFβi, PDGF-B rnRNAs and their relevant proteins in cultured alveolar type Ⅱ cells. (2) The positive expression of TGFβ1, PDGF-B rnRNAs and their proteins were prominent in the proliferative alveolar type Ⅱ cells of experimental group of silicotic models. Weak expression of TGFβ1 mRNA were found only in a part of normal alveolar type Ⅱ cells of control group. ConclusionThe proliferative alveolar type Ⅱ cells express TGFβ1 and PDGF-B, which may play an important role in silicotic fibrcsis.