INFLUENCE OF VENOUS CONGESTION ON BLOOD-LYMPH TRANSPORT OF FLUID AND LARGE MOLECULES IN THE HEAT-INJURED DOG'S PAW

Abstract

Hind paws of anesthetized dogs were exposed to moderate continuous heat (45-52°C).  Lymph flow (L) was increased to 5.61 (SD 3.26)  times  control levels, lymph:plasma concentration ratios for  total plasma protein  (RT)  were  increased  to  3.23  (SD 1.33), and for  exogenous  Dextran-110  (RD)  to  8.41 (SD 4.00) times control levels. Selectivity of the blood-lymph  barrier  for  individual   plasma  proteins was also decreased.  Elevation  of  venous  pressure during  heating  resulted  in  an  increase  of   L  in  5  out of  8  experiments ,  with  no consistent  change  in  RT or RD.  Increased  protein  flux  was  thus  closely coupled to increased  volume  flow.  These  observations are  consistent  with  the  presence  and persistence of intercellular openings or gaps in the microvascular endothelium.