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Anat Embryol (Berl). 1975 Sep 25;147(3):273-92. doi: 10.1007/BF00315076.

Evolution of mesenchymal cells in fetal rat lung.

Anatomy and embryology

A J Collet, G Des Biens

PMID: 1211654 DOI: 10.1007/BF00315076

Abstract

The evolution of connective tissue cells in the developing fetal rat lung is studied under the electron microscope from the 15th until the 21st day of gestation and is compared to the evolution of epithelial cells. Three successive types of stem cells ("mesocytoblasts") are present during the first stages of lung development studied (15 to 18 days of gestation). These stem cells appear to be able to differentiate into fibroblasts or into smooth muscle cells, according to their localization along the broncho-alveolar tubule. Myoblasts are situated near the bronchial epithelium, whereas fibroblasts occur under the alveolar epithelium. Epithelo-mesenchymal interactions are assumed to play a role in this differentiation process. Synthesis of both, collagen and elastic fibers and of cytoplasmic filaments by fibroblasts as well as by myoblasts reveal the multiple potentialities of the mesenchymal stem cell and suggest a common origin. The early fibroblast in characterized by long cytoplasmic processes which contain numerous cytofilaments, and by the presence of collagen fibers in the vicinity of the cell. Later on, (20 days of gestation) the mature fibroblast of the lung mesenchyme shows areas of RER, glycogen and lipidic vacuoles in its cytoplasm. Cytofilaments are numerous within very long cytoplasmic processes and elastic and collagen fibers are very frequent beside the cytoplasmic membrane. The earliest fibroblast differentiation occurs under the epithelium of primitive respiratory bronchioles, which indicate the limit between the bronchial and the alveolar territories. Later on, differentiating fibroblasts are found throughout the whole alveolar walls. Connective tissue cells other than mesenchymal stem cells, fibroblasts or myoblasts are observed during lung development. Vacuolar cells, similar to Hofbauer cells, transiently appear on the 16th day of gestation. On the 20th and the 21st day macrophage-like cells are present in the septal space of the alveolar wall. The absence of intermediate stages of differentiation and parallel evolution of blood cells suggest that those connective tissue cells are differentiated elsewhere and have then migrated from blood into lung mesenchyme. No cell death has been observed in the developing lung.

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References

  1. J Embryol Exp Morphol. 1968 Sep;20(2):151-67 - PubMed
  2. J Biophys Biochem Cytol. 1960 Dec;8:719-60 - PubMed
  3. J Exp Med. 1968 Sep 1;128(3):415-35 - PubMed
  4. J Cell Biol. 1971 Apr;49(1):226-9 - PubMed
  5. Int Rev Exp Pathol. 1964;3:329-63 - PubMed
  6. Z Anat Entwicklungsgesch. 1972;137(3):270-84 - PubMed
  7. Pediatrics. 1963 Dec;32:976-94 - PubMed
  8. Z Zellforsch Mikrosk Anat. 1969;95(3):377-95 - PubMed
  9. J Pathol. 1970 Oct;102(2):61-8 - PubMed
  10. Rev Fr Etud Clin Biol. 1967 Mar;12(3):223-37 - PubMed
  11. Anat Rec. 1969 Dec;165(4):467-83 - PubMed
  12. Anat Rec. 1970 Jun;167(2):231-6 - PubMed
  13. J Cell Biol. 1962 Nov;15:363-77 - PubMed
  14. J Cell Biol. 1968 Sep;38(3):615-27 - PubMed
  15. J Ultrastruct Res. 1958 Nov;2(1):28-54 - PubMed
  16. J Biophys Biochem Cytol. 1961 Dec;11:736-9 - PubMed
  17. Am Rev Respir Dis. 1959 Jul;80(1, Part 2):5-23 - PubMed
  18. Z Anat Entwicklungsgesch. 1972;138(2):111-26 - PubMed
  19. J Ultrastruct Res. 1969 Dec;29(5):470-84 - PubMed
  20. Z Anat Entwicklungsgesch. 1970;132(4):325-38 - PubMed
  21. Anat Rec. 1970 Sep;168(1):43-53 - PubMed
  22. J Ultrastruct Res. 1967 May;18(3):354-76 - PubMed
  23. J Cell Biol. 1971 Jul;50(1):172-86 - PubMed
  24. J Anat. 1971 Dec;110(Pt 3):363-5 - PubMed
  25. Am J Obstet Gynecol. 1967 Jan 15;97(2):235-48 - PubMed
  26. J Anat. 1970 Nov;107(Pt 3):505-18 - PubMed
  27. J Embryol Exp Morphol. 1961 Dec;9:628-33 - PubMed
  28. Am J Pathol. 1968 Jan;52(1):177-210 - PubMed
  29. J Anat. 1950 Jul;84(3):303-18 - PubMed
  30. J Cell Biol. 1974 Feb;60(2):375-92 - PubMed
  31. J Anat. 1971 Dec;110(Pt 3):367-82 - PubMed
  32. Lab Invest. 1964 Oct;13:1215-29 - PubMed
  33. J Anat. 1964 Apr;98:183-93 - PubMed
  34. Am J Anat. 1972 Jun;134(2):221-37 - PubMed
  35. J Cell Biol. 1973 Aug;58(2):265-83 - PubMed
  36. Acta Anat (Basel). 1971;79(4):445-65 - PubMed
  37. J Morphol. 1970 Sep;132(1):69-87 - PubMed
  38. J Pathol. 1970 Jan;100(1):1-7 - PubMed
  39. Am J Anat. 1970 Feb;127(2):181-205 - PubMed
  40. J Cell Biol. 1965 Apr;25:157-61 - PubMed
  41. Anat Rec. 1974 Jul;179(3):343-59 - PubMed
  42. J Cell Biol. 1972 Mar;52(3):577-88 - PubMed
  43. Okajimas Folia Anat Jpn. 1966 May;42(2):149-69 - PubMed
  44. J Cell Biol. 1964 Jul;22:227-58 - PubMed
  45. Cytologia (Tokyo). 1972 Sep;37(3):399-414 - PubMed
  46. C R Hebd Seances Acad Sci. 1961 Jun 12;252:3879-81 - PubMed
  47. Dev Biol. 1973 Aug;33(2):229-40 - PubMed
  48. Hum Pathol. 1974 Jan;5(1):55-67 - PubMed

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