Clot Retraction as a Quantitative Test of the Function and Agglutinability of the Blood Platelets

Abstract

By detn. of the clot retraction in citrated plasma it is shown that a factor, which exerts an inhibitory action on the retraction and produces a simultaneous agglutination of the platelets, is present in yeast cells and red blood cells. This effect, which may also be produced by epinephrine occurs only under strictly aerobic conditions and is inhibited by ascorbic acid, para-aminobenzoic acid, and by heating to 42[degree] C for 2 hrs. Platelet-containing plasma allowed to stand at 37[degree] C for 24 hrs. under anaerobic conditions loses its'' retraction power. At the same time, some agglutination occurs between platelets and leukocytes. This effect on the platelets may be abolished by addition of glucose or fructose to the plasma prior to the expt. An agglutination of the platelets is shown to occur without a simultaneous formation of fibrin, partly under aerobic conditions (possibly due to an action of peroxides) and partly under anaerobic conditions due to incomplete oxidation.