Rheology of peripheral LYMPH

Abstract

Lymph formation and lymph flow involved in the “inner circulation” (Eppinger) as vital events are influenced by histomechanics and physico-chemical factors. The flow dynamics of lymph flow resulting from microcirculation have recently been attributed to an own discipline, the “perihemorheology” (Copley, Witte). Visualization of flow phenomena just at the origin of the lymph vascular system needs some technical requirements encompassing appropriate tissue models and optimum equipment for microscopy, recording, and flow analysis. A review on the history of observations on lymph flow phenomena is given. New approaches are described referring to the rat tongue as appropriate organ for studies of peripheral lymph flow. New techniques based on the use of fluorescent flow markers are applied. Flow registration is made by “maximum trace image” technique. Characteristic now patterns such as partial and parallel streams, fountain-like and jet-like currents are found in initial lymphatics. Rhythmic lymph now caused by breathing and suction activity of the lymph collectors. Transport of labelled cells in peripheral lymph could be registered as well. The interaction of peripheral lymph now with the highly specialized endothelium provides an effective filter function for the elimination of particulate matter by absorption and phagocytosis assigning to the prenodal sector of the lymphatic system an important defence task. Moreover, endothelial interaction with different cells (leucocytes, macrophages, mast cells) suggests additional functions for immunobiological mechanisms and control of vascular permeability of fine lymphatics.