Inhibitory Effect of Interferons on Contractive Activity of Bovine Mesenteric Lymphatic Vessels and Nodes

Resumo

We studied the effect of IFNα-2b and IFNβ-1a on phasic and tonic contractions of isolated bovine mesenteric lymphatic vessels and nodes. IFNα-2b and IFNβ-1a in concentrations of 250-1000 U/ml produced dose-dependent negative chronotropic and inotropic effects on spontaneous phasic contractions and tonus of lymphatic vessels and nodes. In de-endothelialized lymphatic vessels and nodes, IFNα-2b and IFNβ-1a in the same concentrations had less pronounced inhibitory effect on spontaneous contraction and tonus. L-NAME (100 μM) and charybdotoxin (0.1 μM with 0.5 μM apamine) significantly attenuated the inhibitory effect of IFNα-2b on phasic and tonic contractions of lymph nodes. L-NAME (100 μM) and indomethacin (10 μM) significantly reduced the IFNα-2b-induced inhibitory effect on phasic and tonic contractions of lymph node. These results indicate that IFNα-2b and IFNβ-1a have a pronounced inhibitory effect on the phasic and tonic contractions of bovine mesenteric lymphatic vessels and nodes. The responses are endothelium-dependent and are determined by production of NO and endothelium-dependent hyperpolarizing factor by endotheliocytes in lymphatic vessels and by production of NO and prostacyclin by endotheliocytes in the lymphatic nodes.