Sites of leukocyte sequestration in the pulmonary
microcirculation.
Gebb, Sarah A., Jacquelyn A. Graham, Christopher C. Hanger, Patricia
S. Godbey, Ronald L. Capen, Claire M. Doerschuk, Wiltz W. Wagner, Jr.
Departments of Anesthesia, Physiology/Biophysics, and Pediatrics,
Indiana University School of Medicine, Indianapolis, IN 46202, and
Department of Biology, The Colorado College, Colorado Springs, CO
80903
APStracts 2:0156A, 1995.
The location and mechanisms of leukocyte sequestration in the
pulmonary circulation have been investigated using high magnification
in vivo video microscopy to record the passage of unlabeled, native
leukocytes through canine pulmonary capillaries. Of 650 leukocytes
traversing capillary networks, 46 +/- 6 (SE) % of the leukocytes
passed through without stopping, 42 +/- 9% stopped in segments
between junctions, and 12 +/- 4% stopped in junctions. Leukocytes
rolling along arteriolar walls were nearly spherical, as 94% had
aspect ratios (major axis divided by minor axis) /=1.25). Venular rolling was blocked by
fucoidin (blocking both L- and P-selectin) but not by anti-P-selectin
antibodies alone indicating that rolling leukocytes adhered to
venular endothelium by L-selectin. These observations demonstrate
that leukocytes deform to transit the capillary bed, that they stop
more frequently in segments than in junctions, and that rolling
leukocytes in the venular marginated pool adhere via L-selectin.
Received 12 December 1994; accepted in final form 5 April 1995.
APS Manuscript Number A1262-4.
Article publication pending Journal of Applied Physiology.
ISSN 1080-4757 Copyright 1995 The American Physiological Society.
Published in APStracts on 19 April 1995.