Expression of adhesion molecules on circulating pmnl during
hyperdynamic endotoxemia.
Holzer, Katharina, Thiel, M., Moritz, Sandra, Kreimeier, U. and
Messmer, K.
Institute for Surgical Research and Department of Anaesthesiology,
Klinikum Grosshadern, Ludwig-Maximilians-University Munich,
Germany
APStracts 3:0098A, 1996.
In a porcine model of hyperdynamic endotoxemia we studied the numeric
expression of L-selectin and [beta]2-integrins on circulating
polymorphonuclear leukocytes (PMNL). Functional changes of [beta]2
-integrins were determined by the adhesion of PMNL to C3-coated
zymosan particles. Anaesthesized pigs received a continuous infusion
of Salmonella abortus equi endotoxin (5 [mu]g/kg bw *h) for 270 min
(Endotoxin; n=7). A control group received NaCl 0.9% (n=6). L
-selectin had decreased 30 min after the induction of endotoxemia
(59.1 +/- 11.9 relative fluorescence units (RFU) vs. 91.6 +/- 15.5
RFU at baseline (p<0.05), reaching minimal values after 150 min
(23.9 +/- 3.9 RFU vs. 95.2 +/- 30.4 RFU in control group, p<
0.05). PMNL adhesion to C3-coated zymosan increased at 30 min (41.3
+/- 9.9% vs. 2.4 +/- 1.1% in control group, p<0.05) and remained
significantly elevated thereafter. In contrast to the rapid shedding
of L-selectin and functional upregulation of [beta]2-integrins the
numeric expression of [beta]2-integrins remained unchanged until 60
min (44.8 +/- 2.8 RFU vs. 32.2 +/- 1.7 RFU at baseline, p<0.05);
as compared to the control group, significantly elevated values were
observed 150 min after the start of endotoxin (48.9 +/- 2.4 RFU in
group Endotoxin vs. 36.5 +/- 2.7 RFU in controls, p< 0.05). We
conclude that numerical and functional expression of [beta]2
-integrins are dissociated during endotoxemia. Although upregulation
of [beta]2-integrins might render PMNL more adhesive to the vascular
endothelium, the presence of activated PMNL in the circulation
suggests that low expression of L-selectin might impede adhesion.
Received 19 January 1995; accepted in final form 2 February 1996.
APS Manuscript Number A63-5.
Article publication pending Journal of Applied Physiology.
ISSN 1080-4757 Copyright 1996 The American Physiological Society.
Published in APStracts on 14 February 96