The Role of Hydrogen Sulfide in the Dilatation of Mesenteric Lymphatic Vessels in Bulls.

We studied the effects and mechanisms of action of NaHS, an H2S donor, on bovine isolated mesenteric efferent lymphatic vessels pre-contracted with phenylephrine. NaHS induced concentration-dependent relaxation of lymphatic vessels. Removal of the endothelium reduced, but did not completely abolish the relaxing effect of NaHS. Application of NO synthase inhibitor L-NAME, soluble guanylyl cyclase inhibitor ODQ, blocker ATP-sensitive K+ channels glibenclamide, and a combination of blockers of Ca-activated K+ channels of small and intermediate conductance charybdotoxin and apamin attenuated relaxation of lymphatic vessels. Thus, H2S produces a pleiotropic effect on lymphatic vessels; vasorelaxant effect is achieved by several parallel mechanisms. H2S induces relaxation of lymphatic vessels and modulates the rate of lymph transport, thereby affecting the development of immune processes in the body.