Active and passive mechanical properties of the wall of the lymphangion

: The modules of elasticity of circular stripes of lymphangion wall were 3.5.10(4) N.m-2, and those of longitudinal stripes were 1.5.10(5) N.m-2. The module of elasticity of intact lymphangions ranged from 1.2.10(4) to 5.2.10(4) N.m-2. The volume-pressure relationship in intact lympangions were similar to length-force relationship in circular stripes. Spontaneous contractions were only evoked by distention of circular stripes. These findings suggest that smooth muscle of circular layer of lymphangion's wall seems to play a basic role in pumping function of lymphangions.