AJP - Heart and Circulatory Physiology, Vol 246, Issue 6 818-H823, Copyright © 1984 by American Physiological Society
Effect of plasma and red blood cells on water permeability in cat hindlimb
P. D. Watson
Capillary filtration coefficient (CFC) was measured to investigate the
effect of blood in the perfusate of an isolated, maximally vasodilated cat
hindlimb. CFC was measured during perfusion with several different
perfusates: a blood-albumin mixture, albumin alone, a plasma-albumin
mixture, and a plasma-albumin mixture containing varying volumes of red
blood cells. In some experiments the plasma was ultrafiltered to remove
low-molecular-weight components. It was found that perfusion with albumin
alone usually raised CFC above the level found with the blood-albumin
mixture, plasma could reduce the CFC when CFC was elevated above that value
obtained with the blood-albumin mixture, ultrafiltered plasma failed to
reduce CFC when CFC was elevated, and the red cell content of the perfusate
had no influence on CFC over the hematocrit range of 0-20% when the plasma
solute concentrations were kept constant. It was concluded that the
reduction of CFC by blood was caused by a small molecule (less than 10,000
mol wt) present in plasma.
