When platelets encounter a damaged vessel wall, they immediately recognize and adhere to exposed collagen and other subendothelium proteins. The adherent platelets become activated and recruit other platelets to the site of vascular injury. Meanwhile, the initiation of the coagulation cascade generates thrombin, which further activates platelets. By the combined action of thrombin and collagen, platelets express on their surface a number of specific molecules that promote both thrombin formation and cell-cell interactions (COAT platelets). It has been suggested that desmopressin infusion enhances formation of COAT platelets and thus improves the hemostatic activity of platelets.