IN-VITRO PARAOXON (E-600) EXPOSURE - NO ACTIVATING EFFECT ON HUMAN BLOOD-COAGULATION

The in vitro effects of the organophosphorus compound (OPC) paraoxon ( POX) on human blood coagulation were assessed by fibrin monomer (FM) c oncentration measurements and thrombelastographic (TEG) determinations . Increasing doses of POX dissolved in alcohol (POX ALO) or alcohol (A LO) only in corresponding quantities were added to blood drawn from si x human volunteers. In both series (POX + ALO and ALO-only) FM concent rations increased in comparison to the baseline levels. No statistical ly significant differences exist, however, between FM measurements per formed on blood with POX + ALO and those performed on blood with ALO-o nly. No coagulation-activating effect of POX in vitro was demonstrable ; the changes seen in vitro are due to the ALO used as a vehicle. The thrombelastographic parameters showed several changes in the POX + ALO series as dosage increased. At high POX levels, reaction time r and c lot formation time k became longer than in the baseline measurements, the clot formation rate a and the maximum amplitude MA were reduced. T he TEG changes indicate a hypocoagulable state, probably due to the PO X effect on platelet function and/or inhibition of clotting factors (s erine proteases). (C) 1997 Elsevier Science Ireland Ltd.