AJP - Heart and Circulatory Physiology, Vol 244, Issue 1 89-H96, Copyright © 1983 by American Physiological Society
Peritoneal lymphatic uptake of fibrinogen and erythrocytes in the rat
M. F. Flessner, R. J. Parker and S. M. Sieber
Intact and thoracic duct-cannulated rats were dialyzed at various
intraperitoneal pressures with 5% bovine serum albumin solutions containing
125I-fibrinogen or 51Cr-erythrocytes. Lymphatic transport rates were
calculated from the mass of tracer passing into the plasma space as
function of tracer concentration in the peritoneal fluid during dialysis
periods ranging between 143 and 360 min. Peritoneal protein concentrations
were constant over the duration of the experiments. The calculated lymph
flow rate was independent of intraperitoneal pressure and in intact rats
averaged 2.85 +/- 1.22 microliters/min for uptake of 125I-fibrinogen and
2.60 +/- 1.17 for uptake of 51Cr-erythrocytes. However, the observed fluid
loss rates from the peritoneal cavity were sensitive to the intraperitoneal
pressure and were 5 to 20 times the calculated lymph flow rate. Mass
balance experiments in two rats dialyzed with 125I-fibrinogen indicated
that a significant proportion (28%) of tracer leaving the peritoneal cavity
is absorbed by the anterior muscle wall of the abdomen and is probably
trapped there because of its large molecular weight. Results from
125I-fibrinogen and 51Cr-erythrocyte uptake experiments both indicated that
only approximately 30% of the total lymphatic drainage of the peritoneal
cavity passes through the thoracic duct in rats.
