title: [Structural-functional organization of dark and light smooth myocytes in the musculature of visceral organs].
abstract: Using electron microscopy, the smooth musculature of human and laboratory animal bronchi, intestine and ureters was found to contain smooth myocytes of light and dark types, which had the cytoplasm of different electron density. Both types of myocytes are characterized by a high degree of differentiation. The significant differences between light and dark myocytes were detected in the ultrastructural organization of their contractile elements. On the basis of data obtained, light and dark myocytes should be considered as mature cells in different phases of their functional activity. Some part of them, light myocytes, are in the state of "passive" contraction and may serve as a tissue functional reserve. Mutual transformation of light and dark myocytes seems to be possible and may be caused by functional requirements, which are realized at the level of tissue regulation.
authors.forename: A L
authors.initials: AL
authors.lastname: Zashikhin
authors.forename: Ia
authors.initials: Ia
authors.lastname: Selin
authors.forename: Iu V
authors.initials: IuV
authors.lastname: Agafonov
mesh_terms: D000818:Animals; D001980:Bronchi / Q000166:cytology / Q000648:ultrastructure; D006801:Humans; D007422:Intestines / Q000166:cytology / Q000648:ultrastructure; D051379:Mice; D032389:Myocytes, Smooth Muscle / Q000502:physiology / Q000648:ultrastructure*; D014513:Ureter / Q000166:cytology / Q000648:ultrastructure