PLATELETS AND THE SPONTANEOUS SYNERESIS OF BLOOD CLOTS

Abstract

The conflict of opinion regarding the role of the platelets in the syneresis of blood clots may be traced to differences in the methods of counting platelets and of estimating syneresis, and to the use of the term "syneresis" to designate the retraction of a clot both spontaneously and after its artificial separation from the sides of the vessel. An arbitrary standard for irretractility of a clot having been set, exps. involving the addition of intact and destroyed platelets from man and dog and of anti-platelet serum to normal or deplateletized blood or plasma indicated that: The platelet-free plasma of man and dog has all the elements needed for spontaneous syneresis, but adhesion of the clot to the sides of the vessel, if extensive enough, may delay or prevent it. An adequate number of intact platelets improves the degree of syneresis in general and will overcome adhesion of the clot when present. These properties appear to belong only to the unmodified blood platelet and are not species specific.