Effect of storage on platelet release and aggregation responses

The effect of storage conditions on the aggregation and release responses of platelets have been investigated, using ADP as activating agent and beta-thromboglobulin (BTG) as a measure of the release reaction. Spontaneous release of BTG during storage was also investigated. Platelets held at room temperature maintained their ability to aggregate and release BTG in response to ADP after 3 days storage. After storage for 1 day at 4 degrees C platelets showed normal aggregation in response to ADP but did not release BTG. After 4-6 days, platelets stored at room temperature showed a smaller spontaneous loss of BTG than those stored at 4 degrees C. Spontaneous release of BTG from platelets in whole blood stored at 4 degrees C was significantly lower than from platelets stored as concentrates, although platelets prepared from whole blood stored for 1 day showed neither release nor aggregation in response to ADP stimulation. We suggest that ADP-stimulated BTG release may be a sensitive tests of platelet function during storage.