<prompt> All are present in dense granules of platelets EXCEPT:ADPvWFCalciumSerotonin  <response>: Vwf REF: Ganong 22 ed chapter 27 Platelet has a Dense granules: contain the non-protein substances that are secreted in response to platelet activation, including serotonin, ADP, and other adenine nucleotides bAlpha granules: contain secreted proteins other than the hydrolases in lysosomes. These proteins include clotting factors and platelet-derived growth factor PDGF. c Platelet membranes contain receptors for collagen, ADP, vessel wall von Willebrand factor , and fibrinogen 