The Effect of Urea on the Aggregation of Normal Human Platelets

Abstract

Studies have been performed on the effect of urea on platelet aggregation. Over a wide concentration range, urea initially inhibits and later enhances aggregation induced by ADP, thrombin, adrenaline and nor-adrenaline. Urea induces aggregation by a mechanism which differs from that due to ADP and it is suggested that this may reflect platelet damage. Urea alone cannot be held responsible for the qualitative platelet abnormalities and bleeding tendency of the uraemic state, but it may number among a group of harmful influences. ^* Supported by the Post-Graduate Medical Foundation of the University of Sydney.