title: Desensitization of human platelets by platelet activating factor.
abstract: Human platelets are less responsive to PAF at 37 degrees than at 25 degrees. They can be desensitized to the effects of PAF by pre-exposure to small concentrations. In both cases desensitization appears to be accompanied by a decreased affinity of the high affinity site for PAF rather than loss of binding sites. Alteration of a metabolic step subsequent to binding cannot be excluded, but platelets show normal response to a variety of other agents under the conditions resulting in desensitization of platelets to PAF.
mesh_terms: D000244:Adenosine Diphosphate / Q000494:pharmacology; D001792:Blood Platelets / Q000187:drug effects*; D003094:Collagen / Q000494:pharmacology; D004305:Dose-Response Relationship, Drug; D004837:Epinephrine / Q000494:pharmacology; D006801:Humans; D007700:Kinetics; D010972:Platelet Activating Factor / Q000494:pharmacology*; D010974:Platelet Aggregation / Q000187:drug effects; D013696:Temperature; D013917:Thrombin / Q000494:pharmacology
chemical_list: D010972:Platelet Activating Factor; D000244:Adenosine Diphosphate; D003094:Collagen; D013917:Thrombin; D004837:Epinephrine