[Organization of the muscular component of the lymphangion wall in different parts of the lymphatic bed].

Complex comparative analysis of the organization of smooth muscle (SM) forming the wall of lymphatic vessels in bovine small intestinal mesenterium was performed using the methods of morphometry, quantitative histochemistry (including the analysis of nuclear DNA content, and cytoplasmic protein content) and electron microscopy. SM cells (SMC) isolated by dissociation were studied and were found to possess various levels of differentiation, associated with specific morphometric and metabolic characteristics. The structure of SMC population was shown to vary in both different parts of lymphatic bed and within the wall of an individual lymphangion. The results obtained indicate the cellular heteromorphism of lymphatic bed SM. The peculiarities of SM organization in lymphatic vessels are functionally dependent and are determined not only by the level of SM representation in their wall but also by the proportions of different SMC types.

[Ultrastructure of smooth myocytes of small extraorganic lymphatic vessels]. / Ul'trastrukturnaia organizatsiia gladkikh miotsitov melkikh vneorgannykh limfaticheskikh sosudov cheloveka.

Leiomyocytes in musculature of small extraorganic human lymphatics were studied by means of electron microscopic method. Organization of the precollector wall muscular component indicates heterogeneity of smooth myocytes population and specific character of intercellular communications which is probably determined by peculiarities of these lymphatic bed link. In smooth myocytes population "light" and "dark" cells and "synthetic" type leiomyocytes were found. A problem on the role of endothelium and leiomyocytes interaction in mechanisms of regulation of precollector musculature contraction is under discussion. It was suggested that small extraorganic lymph vessels with muscular component in their wall provide lymph flow while the zones with random or single muscular elements are more often connected with intercellular fluid absorption.