Lymph pump mechanics in the rabbit hind leg.
Ikomi, Fumitaka, and Geert W. Schmid-Sch[diaeresis]onbein.
Department of Bioengineering and Institute for Biomedical
Engineering, University of California, San Diego, La Jolla, CA 92093
-0412
APStracts 2:0532H, 1995.
The mechanisms that govern the fluid uptake by the initial lymphatics
and adjustment of lymph flow rates remain to a large degree
uncertain. The aim of this study was to examine how passive tissue
movement contributes to lymph flow rates. Lymph fluid was collected
via a cannulus inserted into one of the popliteal prenodal lymphatics
in the rabbit hindleg. Lymph flow rates were measured during periodic
whole leg rotation and controlled oscillatory massage of the dorsal
skin of the foot. Without whole leg rotation, lymph flow remained at
low values (less than 0.01 ml/h). Introduction of whole leg passive
rotation caused a frequency dependent increase in lymph flow rates
which were increased linearly with the log of frequency between 0.03
Hz and 1.0 Hz. Local skin massage in the region of the initial
lymphatics also led to a similar increase of lymph flow rates
dependent on frequency as well as amplitude of skin displacement.
Lymph flow rates during local skin massage reached a comparable order
of magnitude irrespective of whether the animal was alive or the
heart had been arrested, suggesting that local lymph flow rates can
be adjusted by periodic tissue motion independent of capillary fluid
filtration pressures. The results indicate that periodic expansion
and compression of initial lymphatics provides a mechanism for lymph
pumping.
Received 30 October 1995; accepted in final form 15 November
1995.
APS Manuscript Number H1013-5.
Article publication pending Am. J. Physiol. (Heart Circ. Physiology).
ISSN 1080-4757 Copyright 1995 The American Physiological Society.
Published in APStracts on 8 December 95