[Inhibition by pentoxifylline of procoagulant activity produced by endotoxin-active monocytes].

When appropriately stimulated, monocytes are able to initiate blood coagulation through the membrane expression of tissue factor. This procoagulant activity is thought to play a role in activating coagulation in response to inflammatory stimuli in vivo. We found that pentoxifylline, a methylxanthine derivative already reported to regulate some monocyte functions, inhibits the procoagulant activity developed by monocytes in vitro in response to endotoxin. This effect was accompanied by an early increase in intracellular levels of cyclic AMP and was mimicked by compounds that induce an increase in cyclic AMP levels. These results suggest that the suppressive effect of pentoxifylline occurs at least in part via an increase in intracellular cyclic AMP levels.