Am. J. Respir. Crit. Care Med.,
Volume 158, Number 2, August 1998, 477-483
In Vivo Study of the Effect of Systemic Hypoxia on
Leukocyte-Endothelium Interactions
NATHALIE
BAUDRY,
GAWIYOU
DANIALOU,
JORGE
BOCZKOWSKI,
and
ERIC
VICAUT
Laboratoire d'Etude de la Microcirculation et Département de Biophysique, Hôpital F. Widal; and INSERM U408,
Faculté de Médecine X. Bichat, Paris, France
To evaluate the effect of systemic hypoxia on leukocyte-endothelium interactions in peripheral tissues, we studied by intravital microscopy leukocyte rolling velocity and adherence in venules of rat
cremaster muscle. We examined the possible roles of changes in blood oxygenation, peripheral tissue
oxygenation, changes in local shear rate, and the involvement of integrins. Six groups of rats submitted to either control normoxic conditions, or systemic hypoxia (PO2 = 51 mm Hg) associated with either low O2 tension of Krebs superfusing the muscle, high O2 tension of the Krebs superfusing the
muscle, anti-lymphocyte function-associated antigen (LFA)-1
antibody, pentoxifylline, or normoxic
conditions associated with partial occlusion of the artery perfusing the muscle. We found that: (1)
systemic moderate hypoxia resulting from purely respiratory disturbance even in the absence of local
stop-flow phenomenon or circulatory shock can induce an increase in leukocyte adhesion and a decrease in leukocyte rolling velocity in the microcirculation of peripheral tissues; (2) to be present, this
increase in leukocyte adhesion does not require tissue hypoxia of the peripheral tissue but the effect
of systemic hypoxia on rolling velocity is prevented by tissue oxygenation; (3) this increase in leukocyte adhesion is mediated by CD11/CD18 integrins but is not due to changes in local shear rate.