Influence of pentoxifylline on membrane thrombomodulin levels in endothelial cells submitted to hypoxic conditions.
Thrombomodulin (TM) expression at the surface of endothelial cells is upregulated by cAMP analogues, whereas hypoxic conditions induce a decrease in this expression. Pentoxifylline (PTX) enhances the intracellular levels of cAMP in human umbilical vein endothelial cells (HUVECs). We therefore investigated the influence of this drug on TM expression in cells submitted to hypoxia. TM expression was quantified at the surface of HUVECs in the presence or absence of PTX during 18 h of incubation. Membrane TM was immunolabeled with a fluorescent monoclonal antibody and the expression was quantified by flow cytometric analysis. Our preliminary data revealed that PTX at 0.01 microM significantly increased TM expression levels compared with cells in hypoxia without the drug. Therefore, at this low dose PTX appears able to counterbalance the procoagulant effect of hypoxia.
Seigneur
M
M
Laboratory of Hematology, University of Bordeaux II, Bordeaux, France.
Dufourcq
P
P
Belloc
F
F
Lenoble
M
M
Renard
M
M
Boisseau
M R
MR
D002462:Cell Membrane / Q000187:drug effects / Q000378:metabolism; D002478:Cells, Cultured; D004730:Endothelium, Vascular / Q000166:cytology / Q000187:drug effects / Q000378:metabolism*; D005434:Flow Cytometry; D006801:Humans; D000860:Hypoxia / Q000378:metabolism*; D010431:Pentoxifylline / Q000494:pharmacology*; D010726:Phosphodiesterase Inhibitors / Q000494:pharmacology*; D018180:Thrombomodulin / Q000378:metabolism*
D010726:Phosphodiesterase Inhibitors; D018180:Thrombomodulin; D010431:Pentoxifylline