[Ultrastructure of intercellular contacts of smooth myocytes of the respiratory tract].

By means of electron microscopy at various stages of pre- and postnatal ontogenesis in rats and mice intercellular connections of smooth myocytes, included into the bronchial wall composition, have been investigated. Interaction of the smooth myocytes is ensured with numerous and various types of specialized connections. Certain modifications of the nexus structure are described, they, perhaps, depend on the level of conformational changes of connexons--protein molecules, included into its composition and responsible for intensity of transfer of ions and metabolites. Between the smooth myocytes a contact, that was not previously described, is revealed. It is presented with a complex, formed by vesicular structures, concentrated in the area of oriented in parallel electron opaque membrane area of the interacting cells. Owing to the presence of punctate contacts, not only at early stages of development, but also in the definitive tissue, it is possible to consider them as an independent type of specialized connections, and not as immature forms of gap junctions. There are not any essential differences in the structure and distribution of the contacts during the time of the investigation.