Alpha granules, (α-granules) also known as platelet alpha-granules are a cellular component of platelets. Platelets contain different types of granules that perform different functions, and include alpha granules, dense granules, and lysosomes.[1] Of these, alpha granules are the most common,[1] making up 50% to 80% of the secretory granules.[2] Alpha granules contain several growth factors.[3]
| Alpha granule | |
|---|---|
 Alpha granules shown in a platelet | |
| Details | |
| Part of | Platelets |
| Identifiers | |
| Latin | granulum alpha |
| TH | H2.00.04.1.03005 |
| Anatomical terminology | |
Contents
editContents include insulin-like growth factor 1, platelet-derived growth factors, TGF beta, platelet factor 4 (which is a heparin-binding chemokine) and other clotting proteins (such as thrombospondin, fibronectin, factor V,[4] and von Willebrand factor).[5]
The alpha granules express the adhesion molecule P-selectin[6] and CD63.[7] These are transferred to the membrane after synthesis.
The other type of granules within platelets are called dense granules.
Clinical significance
editA deficiency of alpha granules is known as gray platelet syndrome.
See also
editReferences
edit- ^ a b Blair P, Flaumenhaft R (July 2009). "Platelet alpha-granules: basic biology and clinical correlates". Blood Reviews. 23 (4): 177–89. doi:10.1016/j.blre.2009.04.001. PMC 2720568. PMID 19450911.
- ^ Heijnen, H.; Sluijs, P. van der (2015). "Platelet secretory behaviour: as diverse as the granules … or not?". Journal of Thrombosis and Haemostasis. 13 (12): 2141–2151. doi:10.1111/jth.13147. PMID 26391322. S2CID 206159932. Retrieved 3 April 2021.
- ^ Harrison P, Cramer EM (March 1993). "Platelet alpha-granules". Blood Reviews. 7 (1): 52–62. doi:10.1016/0268-960X(93)90024-X. PMID 8467233.
- ^ Whiteheart SW (August 2011). "Platelet granules: surprise packages". Blood. 118 (5): 1190–1191. doi:10.1182/blood-2011-06-359836. PMID 21816838. S2CID 8273132.
- ^ Nurden AT (May 2011). "Platelets, inflammation and tissue regeneration". Thrombosis and Haemostasis. 105 (Suppl 1): S13–33. doi:10.1160/THS10-11-0720. PMID 21479340. S2CID 36934086.
- ^ Orkin SH, Nathan DG, Ginsburg D, Look AT (2009). Nathan and Oski's hematology of infancy and childhood. Elsevier Health Sciences. pp. 1386–. ISBN 978-1-4160-3430-8. Retrieved 2 November 2010.
- ^ Coleman WB, Tsongalis GJ (2009). Molecular pathology: the molecular basis of human disease. Academic Press. pp. 258–. ISBN 978-0-12-374419-7. Retrieved 2 November 2010.
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