Contractile Function of the Capsule of the Bovine Mesenteric Lymph Nodes at the Early Stage of Inflammation

Inflammation is detected not only in infections or injuries, but also in many other pathological processes associated with tissue dysfunction, such as type 2 diabetes mellitus, atherosclerosis, myocardial infarction, etc. In the processes of development and resolution of inflammation in all cases involves the lymphatic system, and in particular the lymph nodes (LN), which receive products of tissue degradation, bacterial fragments, antigen-presenting cells and various cytokines from the focus of inflammation. The aim of the study was to investigate the mechanisms of inhibition of contractile function of the bovine mesenteric LN capsule contributing to LN remodeling at the early stage of inflammation. Isolated LN capsule strips treated with lipopolychasaride (LPS) were examined in a myograph. The data obtained show that when exposed to LPS, the extensibility of the LN capsule increases due to inhibition of the contractile function of the smooth muscle cells that make up the capsule. It was found that the action of LPS leads to the expression of inducible NO synthase, cyclooxygenase-2 and cystathionine-gamma -lyase in the LN capsule cells. NO, prostaglandins and H2S produced by these enzymes not only inhibit the phase contractile function of capsule smooth muscle cells, but also lead to a significant decrease in tone. Produced in significant amounts NO activates the NO -> sGC -> cGMP -> PKG -> K-ATP signaling pathway of smooth muscle cells, in addition, it has a direct effect on other regulatory mechanisms. For the first time, it was shown that H2S synthesized by cystathionine-gamma -lyase in the LN capsule treated with LPS not only has a direct relaxing effect but also enhances NO-mediated relaxation of the capsule smooth muscle cells. Thus, the results of this study provide evidence that changes occur in the bovine mesenteric LN capsule at an early stage of LPS-induced inflammation, aimed at creating conditions for an increase in LN size and accumulation of immune cells.