[Platelets and liver regeneration].

Platelets are the smallest structures in circulating blood and have a convex disc construction with an equatorial diameter of 2-3 microns and have no nucleus. They are derived from megakaryocytes in the bone marrow. Following their normal life span of 8-10 days, they are removed from the circulation when passing through the spleen. Platelets have three types of secretory granules, i.e., alpha-granules, dense-granules, and lysosomal granules in the cytosol (Fig. 1). Each granule contains a specific mix of soluble factors, such as plateletderived growth factor (PDGF), hepatocyte growth factor (HGF), insulin-like growth factor-1 (IGF-1), vascular endothelial growth factor (VEGF), serotonin, adenosine diphosphate (ADP), adenosine tri-phosphate (ATP), epidermal growth factor (EGF), and transforming growth factor beta (TGF-beta) (Blair et al., 2009; McNicol & Israels., 1999; Polasek et al., 2005). After being activated by physiological substances such as thrombin, collagen, thromboxane A2 (TXA2), epinephrine, and platelet-activating factor (PAF), or by nonphysiological substances such as divalent cationophores and phorobol esters, platelets release these biologically active substances that exert various effects depending on the specific context (Holmsen, 1989; Suzuki H et al., 1992; Broos et al., 2011)