Actions of aspirin and dipyridamole on lymphocyte activation

The actions of aspirin and dipyridamole on lymphocyte activation in vitro have been studied. Aspirin inhibits lymphocyte activation when measured by protein synthesis or by 3H-thymidine incorporation at therapeutic concentration. Dipyridamole also strongly inhibits 3H-thymidine incorporation, but is a less potent inhibitor of protein synthesis at therapeutic concentrations. Aspirin/dipyridamole combinations did not show synergism as inhibitors of lymphocyte activation. It is concluded that these drugs has dissimilar actions on the lymphocyte and that dipyridamole will not serve as an aspirin-sparing drug in anti-inflammatory therapy.