Abstract
An effect of plasma components on the maintenance of platelet aggregability was studied. Washed human platelets (WP) were suspended in isotonic buffer containing dialyzed or non-dialyzed plasma, and stored at R. T. The time courses of the aggregability of WP induced by ADP were carried out. The aggregability of all samples at 0 hour, were 80% approximately. However, the aggregability of platelets stored in dialyzed plasma-buffer, decreased more rapidly than that stored in non-dialyzed plasma-buffer. The similar result was obtained when MgCl2 and glucose were added to the dialysis buffer. Then, dialyzed plasma was reconstituted by adding the filterate from Centriflow 25 which contained the low molecular weight (<2500) components in plasma. The reconstituted plasma indicated the similar efficiency to the non-dialyzed plasma on the maintenance of aggregability.
These results show that there are some dialyzable components in plasma which are not necessary for the aggregating reaction, but are necessary for the maintenance of ADP-induced platelet aggregability. It is suggested that they were not Ca2+, Mg2+, glucose and proteins, and their molecular weights are less than 2, 500.
