Changes in Platelet Volume Produced by Temperature, Metabolic Inhibitors, and Aggregating Agents.

Abstract

Summary The volume of normal human platelets, measured with a Coulter Counter, was approximately 5.8 μ³ when the platelets were disc-shaped. Platelet volume increased gradually between 15 and 30% when platelets from ACD blood were maintained at less than 10°;C or incubated with fluoride, or iodoacetate plus cyanide. Platelets from blood anticoagulated with EDTA swelled progressively; this was partially reversed in ACD plasma. Adenosine diphosphate or thrombin in concentrations causing aggregation in platelet-rich plasma induced rapid platelet swelling. ADP-induced swelling was prevented by adenosine monophosphate, but not by arcaine or EDTA, although all three compounds prevented ADP-induced clumping. Epinephrine in a concentration capable of causing aggregation did not produce swelling. All of the conditions which caused platelet swelling were associated with change in shape of platelets from smooth discs to spiny spheres. The technique described for measuring rapid changes in platelet volume should prove useful for studying membrane physiology.