Polymorphonuclear leukocytes (pmn) transit times in the bone marrow
during streptococcal pneumonia.
Terashima, Takeshi, Barry Wiggs, Dean English, James C. Hogg, and
Stephan F Van Eeden.
Pulmonary Research Laboratory, University of British Columbia, St.
Paul's Hospital, Vancouver, B.C. V6Z, 1Y6, Canada
APStracts 3:0109L, 1996.
The release of polymorphonuclear leukocytes (PMN) from the bone marrow
(BM) is a hallmark of acute inflammatory conditions. Bone marrow
stimulation may increase the toxic potential of these newly released
PMN and influence their behavior at inflammatory sites. The present
study was designed to measure the transit time of PMN in the mitotic
and post-mitotic pools of the BM in rabbit using 5'-bromo-2'
-deoxyuridine (BrdU). Blood samples were obtained at 2-24 h intervals
from 24-192 h after a single BrdU injection and BrdU positive PMN
(PMNBrdU) was detected as they appear in the circulating blood using
immunohistochemistry. The intensity of nuclear staining for BrdU was
used to define a single generation of PMN and graded as either weakly
(G1), moderately (G2) or highly (G3) stained. The mean (and +/-SEM)
transit time of PMNBrdU through the BM was 95.6+/-3.6 h with 51.1+/
-5.9 h in the mitotic and 65.4+/-5.4 h in the post-mitotic pool.
Streptococcus pneumoniae instillation in the lung (n=3) shortened the
transit time of PMN through the BM to 54.0+/-2.6 h with a shorter
time in both the mitotic (36.2 +/- 5.7 h) and the post-mitotic pool
(34.6 +/- 0.8 h). All these values were shorter than the control
values (p<0.05). We conclude that Streptococcus pneumoniae
shortens the transit time of PMN in the mitotic and post-mitotic
pools in the marrow which may result in the release of immature PMN
with higher levels of lysosomal enzymes into the circulation.
Received 27 February 1996; accepted in final form 6 June 1996.
APS Manuscript Number L68-6.
Article publication pending Am. J. Physiol. (Lung Cell. Mol.
Physiology).
ISSN 1080-4757 Copyright 1996 The American Physiological Society.
Published in APStracts on 4 July 96