Alpha granule
Alpha 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. Of these, alpha granules are the most common, making up 50% to 80% of the secretory granules. Alpha granules contain several growth factors.
Contents
Contents include insulin-like [growth factor 1], platelet-derived growth factors, TGF beta, platelet [factor 4] and other clotting proteins.The alpha granules express the adhesion molecule P-selectin and CD63. These are transferred to the membrane after synthesis.
The other type of granules within platelets are called dense granules.