title: Effects of beta-endorphin and met-enkephalin on platelet activity.
abstract: In the present study, beta-endorphin and met-enkephalin were tested for their antiplatelet activity in human platelet-rich plasma (PRP). Blood samples were obtained from 15 healthy subjects. The results of the study show that these two endogenous opioids (200 pg/ml final concentration) reduce platelet aggregation when it is induced by ADP at low dose (0.5 microM). It is likely due to conformational changes on the platelet membrane that cause a non-specific decreased susceptibility to platelet-aggregating agonists.
authors.affiliation: Department of Haematology, Transfusion Medicine and Transplant Immunology, Second University of Naples, Italy.
authors.forename: A
authors.initials: A
authors.lastname: Tirelli
authors.forename: S
authors.initials: S
authors.lastname: Guastafierro
authors.forename: S
authors.initials: S
authors.lastname: Annunziata
authors.forename: R
authors.initials: R
authors.lastname: Guariglia
authors.forename: L
authors.initials: L
authors.lastname: Coppola
mesh_terms: D000244:Adenosine Diphosphate / Q000494:pharmacology; D001792:Blood Platelets / Q000187:drug effects* / Q000502:physiology; D004305:Dose-Response Relationship, Drug; D004744:Enkephalin, Methionine / Q000494:pharmacology*; D006801:Humans; D009994:Osmolar Concentration; D010974:Platelet Aggregation / Q000187:drug effects; D001615:beta-Endorphin / Q000494:pharmacology*
chemical_list: D004744:Enkephalin, Methionine; D001615:beta-Endorphin; D000244:Adenosine Diphosphate