Glucocorticoids stimulate the contractile activity of lymphatic vessels and lymph nodes

Abstract

Objective. The lymphatic network participates in the launch and development of an immune response. From an immunological point of view, the lymph flow, provided by active contractions of the lymphatic vessels, is the process of delivering antigens and antigen-presenting cells to the lymph nodes. The purpose of this study is to study the non-genomic effects and mechanisms of action of glucocorticoids, which are natural immunomodulators, on the transport function of lymphatic vessels and lymph nodes. Materials and methods. Bovine mesenteric afferent lymphatic vessels 1.2-1.5 mm in diameter and lymph nodes were used for the study. The contractile activity of isolated lymphatic vessels and capsules of lymph nodes under the action of glucocorticoids in vitro were studied. Agonists and antagonists of signaling pathways were used to determine the mechanisms of action of glucocorticoids on smooth muscle cells. Results and their discussion. Glucocorticoids in therapeutic concentrations increase the tone of lymphatic vessels and lymph nodes, increase in frequency and a decrease the amplitude of phase contractions. It is shown that glucocorticoids stimulate α-adrenoreceptors of smooth muscle cells due to the increase in their affinity. Glucocorticoids activate in the smooth muscle cells the RhoA / ROCK signaling pathway and inhibit the synthesis of endothelial vasodilators - NO and prostacyclin. The revealed changes in the contractile function of lymphatic vessels and lymph nodes under the action of glucocorticoids underlie the modulation of glucocorticoid transport of lymph and the speed of delivery to the lymph nodes of antigens and antigen-presenting cells, i.e. regulation of immune responses. Conclusions. Non-genomic effects and mechanisms of action of glucocorticoids on the contractile function of lymphatic vessels and nodes have been studied. Glucocorticoids activate smooth muscle cells of lymphatic vessels and nodes by stimulating α-adrenoreceptors, and also inhibit the production of NO and prostacyclin.