Alteration of platelet function in dogs mediated by interleukin-6
J Peng, P Friese, JN George, GL Dale and SA Burstein
Department of Medicine, University of Oklahoma Health Sciences Center,
Oklahoma City 73190.
To determine if interleukin-6 (IL-6) administration influences platelet
function, platelet activation was analyzed sequentially in IL-6-treated (80
micrograms/kg/d) and control dogs. Platelet activation was determined in
whole blood by flow cytometry by quantitating the binding of a monoclonal
antibody to platelet surface P-selectin after stimulation with graded doses
of thrombin. Administration of IL-6 resulted in a twofold decrease in the
thrombin concentration required for induction of half-maximal P-selectin
expression (ED50) compared with control animals. The ED50 returned to
normal after cessation of IL- 6 administration. As measured by P-selectin
expression, enhanced responsiveness to the strong agonist platelet
activating factor (PAF) was also observed in the IL-6-treated dogs. IL-6
had no effect on the susceptibility of platelets to thrombin activation
when incubated with anticoagulated dog blood. The data show that, in
addition to augmenting the platelet count in normal dogs, IL-6 enhances the
sensitivity of platelets to activation in response to thrombin and PAF.
Volume 83,
Issue 2,
pp. 398-403,
01/15/1994
Copyright © 1994 by The American Society of Hematology
