LYMPHATIC CLEARANCE DURING COMPRESSIVE LOADING

GE Miller, J Seale

Abstract


Lymphatic clearance of radicactive sulfur colloid is
measured as a function of externally applied pressure
on the hind limb of mongrel dogs. A dead
weight device is placed over the site of subcutaneous
injection . A solid state Si (Li) is placed into a a
slot at the bottom of the device to continuously re cord
activity of the tracer. An exponential decrease
in activity is modeled as a dual decay resulting
from both tracer half life decay and lymphatic clearance
of the tagged sulfur colloid. External pressure
is seen to enhance lymph clearance until a critical
closing pressure is reached, whereupon the vessel
collapses and lymph flow is drastically reduced. A
closing pressure of 60 mmHg is observed for several
experiments. Lymph flow per tissue volume is see·n
to rise from a mean of 0.324 ml/hr/ml for uncompressed
tissue to 0.96 ml/hr/ml for fully enhanced
flow in other experiments at 60 mmHg. Results at
a pressure of 75 mmHg show almost no lymph
clearance suggesting complete vessel closure.


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