Acetylcholine, Cholinesterase Activity, and the Aggregability of Human Platelets

Washed human platelets and isolated platelet-membrane fractions have been shown to have cholinesterase activity distinct from that of erythrocytes. In intact platelets the cholinesterase activity is affected by thrombin, ADP, epinephrine, or collagen. Other agents were shown to influence cholinesterase activity and seven of these also inhibited platelet aggregation induced by thrombin, ADP, or collagen. The relationship of acetylcholine and cholinesterase activity to platelet aggregation is discussed in light of these findings.