Is ADP Secreted by Platelets?
Yes, ADP is secreted by platelets. More specifically, ADP is actively secreted from platelet dense granules.
Adenosine diphosphate (ADP) plays a crucial role in platelet activation and aggregation. This process is vital for hemostasis, the body's natural process to stop bleeding. When a blood vessel is damaged, platelets adhere to the site of injury and become activated. This activation triggers the release of ADP from their dense granules. The released ADP then acts as a potent agonist, further activating nearby platelets and amplifying the aggregation process. This creates a platelet plug, which helps seal the damaged vessel and prevent further blood loss.
Mechanisms of ADP Release
- Active Secretion: ADP is actively released from platelet dense granules upon platelet activation. This is a key mechanism for amplifying platelet aggregation.
- Passive Release: While active secretion is the primary method, ADP can also be passively released from damaged erythrocytes (red blood cells) and endothelial cells.
ADP's Role in Platelet Aggregation
Several references confirm ADP's role in platelet function:
- PMC200202: This article states that "ADP is actively secreted from platelet dense granules but is also passively released from damaged erythrocytes and endothelial cells."
- PubMed 9444477: This publication highlights ADP's role in inducing platelet shape change and secretion from storage granules.
- American Heart Association: This article describes ADP as an important agonist released from damaged vessels and red blood cells, inducing platelet aggregation.
- Blood: This source details ADP's role as a platelet agonist causing platelet shape change, aggregation, and thromboxane A2 generation.
- ScienceDirect: This article emphasizes that ADP, a component of platelet dense granules, contributes to hemostasis and coagulation.
- Frontiers in Pharmacology: This publication confirms that ADP is released from dense granules during platelet activation.
The release of ADP from platelets is a critical step in the process of blood clot formation.
