EFFECT OF MONOMETHYLMETHACRYLATE ON PROCOAGULANT ACTIVITIES OF HUMAN MONOCYTES AND UMBILICAL VEIN ENDOTHELIAL-CELLS IN-VITRO

Cemented total hip replacement surgery is associated with intraoperati ve cardiorespiratory depression and postoperative proximal deep vein t hrombosis which may be linked to an extreme intraoperative thrombin ge neration and local and systemic effects of monomethylmethyacrylate (MM A) released into circulation from curing cement. This in vitro study d emonstrates that MMA alone or in combination with thrombin have effect s on monocytes and human umbilical vein endothelial cells (HUVEC) whic h modulate their procoagulant activities. Moderate doses of MMA had a slight tissue factor (TF) inducing effect on monocytes. Small doses of MMA (0.1-1 mu g/ml) markedly potentiated the TF inducing effect of th rombin of lipopolysaccharide (LPS) which was included as a reference s timulant. These TF modulating effects of MMA were not seen with HUVEC. However, the generation of fibrinopeptide A(FPA) in cell overlay plas ma indicated enhanced procoagulant activity of HUVEC treated with mode rate doses of MMA, probably reflecting MMA cytotoxicity leading to cel l retraction and exposure of extracellular matrix. Furthermore, small doses of MMA had a slight enhancing effect on FPA generation when coin cubated with thrombin. These findings indicate that MMA in concentrati ons found in central venous blood in vivo, alone or together with thro mbin, directly or indirectly exert effects that contribute to activati on of coagulation.