AJP - Heart and Circulatory Physiology, Vol 246, Issue 2 312-H315, Copyright © 1984 by American Physiological Society
Anoxia and capillary filtration coefficient in the isolated cat hindlimb
P. D. Watson, D. R. Scott and M. B. Wolf
Isolated cat hindlimbs were perfused from a reservoir with an albumin-blood
mixture at a constant flow of 20 ml X min-1 X 100 g muscle-1 while
alternately bubbling the perfusate with either 95% O2-5% CO2 gas mixture or
a 95% N2-5% CO2 mixture for 50- to 60-min periods. Capillary filtration
coefficient (CFC), vascular resistance (R), and perfusate O2 content were
measured in each period. The arterial O2 content fell from fully
equilibrated to 0.25 vol% during the use of N2. R fell from about 6 mmHg X
min X 100 g X ml-1 during O2 bubbling to approximately 1.0 with N2. CFC
averaged 0.012 +/- 0.002 ml X min-1 X mmHg-1 X 100 g muscle-1 (SD, n = 6)
during the 1st O2 period, rising to 0.016 +/- 0.002 (n = 4) in the 3rd O2
period 4 h later. CFC fell by 5% (P less than 0.001) during the periods of
N2 bubbling. Papaverine was present in two experiments without effect on
the CFC data. It was concluded that CFC was not meaningfully influenced by
vascular resistance or anoxia, a finding that is inconsistent with the
concept of local metabolic control of CFC by precapillary resistance
vessels.
