Systemic decrease in murine collecting vessel lymphatic function during initial stages of inflammation (110.5)

Abstract

Abstract The effects of inflammation on the lymphatic system are largely unknown, with conflicting reports of enhanced or decreased activity. We imaged murine lymphatic vessels and function using a custom-designed ICCD camera/low-level laser system and an intradermally injected fluorescent dye, indocyanine green, which is rapidly taken up by the lymphatic vasculature. Mice injected with LPS exhibited a drastic, systemic decrease in collecting vessel lymphatic propulsive flow velocity and frequency at 4-24 hours after the inflammatory insult, gradually increasing to normal values by 7 days post-inflammation. IL-6, TNF-alpha, MCP-1, MCP-5, RANTES, and IL-10 levels were increased in plasma at 4-24 hours. Draining lymph nodes retained ICG at 6-7 days post-inflammation, perhaps indicating restriction of afferent and/or efferent lymphatic vessels. This system for non-invasive imaging of the lymphatic system under inflammatory conditions may allow insights into mechanisms of inflammation and its resolution.