Anticoagulant and lipolytic effects of a low molecular weight heparin fraction

The lipolytic and anticoagulant actions of a 4000 dalton low molecular weight (LMW) heparin were compared with unfractionated mucosal heparin after intravenous and various subcutaneous doses in man. I.v. injection of 100 USP units/kg body weight lipoprotein lipase (LPL) activity, and inhibition of factor Xa decreased with a half life twice as long after LMW heparin compared to normal heparin (p less than 0.05). There were no differences in half lives for HTGL activity, thrombin inhibition and on aPTT. The area under the activity time curve (AUC) of LPL and factor Xa was double with LMW heparin (p less than 0.05). S.c. administration showed that the AUC of LMW heparin on the factor Xa inhibition was 10 times larger compared to normal heparin. LPL activity was released comparable to normal heparin. The effects on HTGL were three times larger compared to normal heparin. There were no differences in half lives. The data show that in contrast to normal heparin LMW heparin is rapidly and completely absorbed from the subcutaneous depots. The pharmacodynamic data of LPL activity and factor Xa inhibition suggest similar release mechanisms.