Lack of effect of heparin on TxA2 binding to platelets

Heparin was reported to potentiate platelet aggregation [l] and to interfere with the antiaggregating effects of PGI*, PGD2 [2] and of other prostanoid (PGE1) and non-prostanoid compounds [3]. Heparin has been demonstrated to bind to specific receptors on the surface of intact human platelets [4] and to interact with other platelet receptors, such as alpha adrenoceptors so reducing their binding affinity [5].