This Article Order Full text via Infotrieve Services Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Mohammad, S. F. Articles by Mason, R. G. Search for Related Content PubMed PubMed Citation Articles by Mohammad, S. F. Articles by Mason, R. G.

American Journal of Pathology, Vol 104, 132-141, Copyright © 1981 by American Society for Investigative Pathology

REGULAR ARTICLES

Effects of heparin on platelet aggregation and release and thromboxane A2 production

SF Mohammad, WH Anderson, JB Smith, HY Chuang and RG Mason

Heparin, when added to citrated platelet-rich plasma (PRP), caused potentiation of platelet aggregation and the release reaction induced by the aggregating agents adenosine diphosphate (ADP), arachidonic acid, collagen, and epinephrine. At low concentrations (4.7 x 10(-5) M) arachidonic acid failed to cause aggregation of platelets in citrated PRP. However, in the presence of heparin, the same concentration of arachidonic acid caused aggregation. Examination of PRP for the presence of thromboxane A2 (TxA2) by use of a bioassay revealed that heparin also stimulated release of TxA2. This finding indicated that platelets released more TxA2 when they were challenged by low concentrations of arachidonic acid in the presence of heparin than in its absence. Platelets were labeled with 3H-arachidonic acid and 14C- serotonin, and attempts were made to determine whether heparin stimulated the platelet release reaction first with subsequent increased production of TxA2, or alternatively, whether heparin stimulated TxA2 production first with subsequent enhancement of the release reaction. In view of the demonstrated simultaneous release of 14C-serotonin and 3H-arachidonic acid metabolites, it appeared that either release of 14C and 3H occurs concurrently or, even if one of these events is dependent on the other, both events take place in rapid succession. Timed sequential studies revealed that in the presence of arachidonic acid, the addition of heparin hastened the apparently simultaneous release of both 14C and 3H.

This article has been cited by other articles:

				E. N. Deliargyris, B. Upadhya, L. G. Melton, C. Thompson, M. Fisher, D. A. Gabriel, G. J. Dehmer, and D. C. Sane Unfractionated Heparin Reduces the Anti-Platelet Effects of Abciximab but not Eptifibatide During PCI. Clinical and Applied Thrombosis/Hemostasis, October 1, 2006; 12(4): 458 - 464. [Abstract] [PDF]

				I. A. Jagroop and D. P. Mikhailidis Heparin Therapy Leads to Platelet Activation and Prolongation of Platelet Function Analyser-100 Closure Time Journal of Cardiovascular Pharmacology and Therapeutics, June 1, 2006; 11(2): 156 - 157. [PDF]

				G. Cianciolo, S. Stefoni, F. Zanchelli, S. Iannelli, L. Coli, L. C. Borgnino, L. B. De Sanctis, V. Stefoni, A. De Pascalis, E. Isola, et al. PDGF-AB release during and after haemodialysis procedure Nephrol. Dial. Transplant., October 1, 1999; 14(10): 2413 - 2419. [Abstract] [Full Text] [PDF]