Inhibition of Adenosine Diphosphate-induced Platelet Aggregation by Histamine

Abstract

IT is now well known that adenosine and adenosine monophosphate (AMP) strongly inhibit the aggregation of human and rabbit platelets which occurs in the presence of adenosine diphosphate (ADP). Adenosine and AMP are effective at a concentration of approximately 10⁻⁷ M, and are the most potent naturally occurring inhibitors known. O'Brien¹ has shown that antihistaminics, anti-malarials, and local anaesthetics, all at approximately 10⁻³ M, inhibit ADP-induced platelet aggregation. It has recently been reported by Salzman and Chambers² that substituted amino-acids, at a concentration of 1.5 × 10⁻² M, inhibit ADP-induced platelet aggregation.