Erythrocyte flux in capillary networks during maturation:
implications for oxygen delivery.
Berg, Bradley R., and Ingrid H. Sarelius.
Department of Biophysics, University of Rochester, School of
Medicine and Dentistry, Rochester, NY 14642
APStracts 3:0224H, 1996.
Erythrocyte (RBC) flow variables were measured using videomicroscopy
in hamster cremaster muscle capillary networks. Capillary networks
consist of subgroups, termed modules, with architectural
characteristics which are invariant with maturation (Berg, B.R., and
Sarelius, I.H. Am. J. Physiol. 268:H1215-H1222, 1995). RBC flux in
modules decreased from 82.0 +/- 4.3(S.E.) cells/sec at 51 days of age
to 59.5 +/- 7.5 and 27.5 +/- 2.8 cells/sec at 65 and 79 days
respectively. Mean cell velocity (vc) at 51 days (385 +/- 10
[mu]m/sec) was higher than at 65 or 79 days (285 +/- 15 and 241 +/-
12 [mu]m/sec respectively). Cell content (N/L) decreased later,
between 65 and 79 days (from 0.21 +/- 0.01 and 0.23 +/- 0.02 to 0.12
+/- 0.01 cells/[mu]m at 51, 65 and 79 days respectively). These
temporal differences in the decrease in vc and N/L suggest different
regulatory mechanisms. The capacity of capillary networks to deliver
O2 was modeled using the calculated PO2 at the capillary wall (2cw)
to indicate the capacity to deliver O2. During maturation, 2cw
remained unchanged (15.5 +/- 1.2 and 11.4 +/- 2.7 torr in maximal
dilation, and 24.5 +/- 1.4 and 22.8 +/- 2.4 torr at rest, at 51 and
79 days respectively). Thus despite changes in RBC flow variables
with maturation, the capacity for networks to deliver O2 remains
constant.
Received 2 November 1994; accepted in final form 20 May 1996.
APS Manuscript Number H975-4.
Article publication pending Am. J. Physiol. (Heart Circ. Physiology).
ISSN 1080-4757 Copyright 1996 The American Physiological Society.
Published in APStracts on 5 June 96