Which receptor is associated with transient aggregation upon activation by ADP?

The receptor associated with transient aggregation upon activation by ADP is P2Y1. This receptor is a G-protein coupled receptor that, when activated by adenosine diphosphate (ADP), facilitates the initial signaling cascade leading to platelet activation and aggregation. Specifically, P2Y1 activation leads to a rapid change in shape of the platelets and a transient aggregation effect, primarily by mediating calcium mobilization.

This early phase of aggregation is critically important as it helps platelets quickly respond to vascular injury, but it is not sustained. Sustained aggregation then involves additional receptors and pathways, particularly the engagement of the P2Y12 receptor, which plays a role in the stabilization of platelet aggregates over a longer time frame. Understanding the distinct roles of these receptors is vital for grasping the complex regulatory mechanisms involved in platelet function and management with antiplatelet therapies.