Platelet (resting state) (None)

Platelets are small, anucleate cell fragments circulating in blood, derived from megakaryocytes. In their resting (unactivated) state, they circulate inertly, maintained by continuous inhibition from endothelial factors such as nitric oxide and prostacyclin. Resting platelets have a distinctive discoid morphology, maintain low intracellular calcium, and possess surface molecules such as glycoprotein Ib-IX-V and GPVI in an unengaged conformation. On blood vessel injury, platelets rapidly transition to the activated state, facilitating adhesion, secretion, and aggregation to form a platelet plug and initiate coagulation. The resting state is crucial for preventing unwanted thrombosis under physiologic conditions. Unactivated platelets do not execute procoagulant functions but have the molecular machinery to respond quickly when activated.

Other names

Resting plateletsquiescent plateletsnon-activated plateletsinactive platelets

Not applicable. Drugs target receptors or signaling molecules involved in platelet activation, e.g., P2Y12 antagonists inhibit ADP-induced platelet activation and aggregation.