ISSN:
0003-276X
Keywords:
Life and Medical Sciences
;
Cell & Developmental Biology
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Medicine
Notes:
The processes of myogenesis and elastogenesis are studied under the electron microscope in developing rat lungs, throughout the 15th to the 21st days of the gestation period. Myogenesis follows bronchial development and stops at the beginning of the alveolar zone, at the primitive respiratory bronchiole level. Elastogenesis appears at the periphery of the myoblasts during their differentiation. Thin myofilaments only are observed within myoblasts and their formation precedes that of dense bodies.Primitive respiratory bronchioles are visible on the 19th day and are characterized by an early elastogenesis carried out by fibroblasts. At this stage there are no elastic fibers around the alveolar tubules. Then (20th and 21st days) elastogenesis spreads throughout the alveolar zone, accompanying the alveolization process. Peculiar morphological characteristics of the pulmonary fibroblast are underlined. In relation to both muscular cells and fibroblasts the fine structural features of the rat pulmonary elastogenesis are identical to those previously described in other organs. Myoblasts and fibroblasts probably originate from the same primitive mesenchymal cell. Their differentiation depends on the zone where they are located. The relations between connective tissue and epithelial cell differentiation suggest a control of lung development by means of reciprocal induction processes.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/ar.1091790306
