title: [Role of adenosine diphosphate in the course of thrombin signal transmission].
abstract: OBJECTIVE
  To study the effects adenosine diphosphate (ADP) on platelet aggregation and expression of glycoprotein (GP) on the surface of platelet membrane after activation of thrombin receptors, so as to investigate its role in thrombin signal transmission.
  
  
  METHODS
  Peripheral blood samples were collected from from 10 healthy volunteers. Platelets were extracted. The thrombin receptor activating peptides (TRAP), protease-activated receptor 1 activated peptide (PAR1-AP, SFLLRN, 25 micromol/L) and PAR4-AP (AYPGKF, 250 micromol/L) were added into the suspension of platelets respectively to induce platelet aggregation. In apyrase inhibition test apyrase II was added into the suspension of platelets for 2 hours and then PAR1-AP or PAR4-AP was added respectively to observe the the expression of GPIb and P-selectin with flow cytometry.
  
  
  RESULTS
  Either PAR1 and PAR4 induced platelet aggregation. After apyrase II stimulation the PAR4-AP induced platelet aggregation was not influenced and PAR1-AP induced platelet aggregation was partially inhibited with a reversible aggregation curve. Stimulated by PAR1-AP and PAR4-AP the GPIb decreased firstly and then gradually returned to normal. Apyrase VII have not significant influence on the GPIb expression, but accelerated the return of GPIb to the platelet surface after PAR1 stimulation so that the lowest point was accelerated to 2 min, compared to that of the control group (5 min) and there were significantly differences 10 and 30 min later between these 2 groups (all P < 0.05). The P-selectin expression was remarkably increased 2 min after the PAR1-AP and PAR4-AP induction and peaked 2 min later. Apyrase VII did not significantly influence the P-selectin expression in these 2 activation ways.
  
  
  CONCLUSIONS
  ADP plays an important role in the thrombin signal transmission, especially in the PAR1 pathway.
authors.affiliation: Jiangsu Institute of Hematology, First Affiliated Hospital of Suzhou University, Suzhou 215006, China.
authors.forename: Yue
authors.initials: Y
authors.lastname: Han
authors.forename: Xiao-xu
authors.initials: XX
authors.lastname: Lu
authors.forename: Zhao-yue
authors.initials: ZY
authors.lastname: Wang
authors.forename: Lan
authors.initials: L
authors.lastname: Dai
authors.forename: Wen-hong
authors.initials: WH
authors.lastname: Shen
authors.forename: De-pei
authors.initials: DP
authors.lastname: Wu
authors.forename: Chang-geng
authors.initials: CG
authors.lastname: Ruan
mesh_terms: D000244:Adenosine Diphosphate / Q000494:pharmacology*; D001081:Apyrase / Q000378:metabolism; D005434:Flow Cytometry; D006801:Humans; D009842:Oligopeptides / Q000494:pharmacology; D019007:P-Selectin / Q000032:analysis; D010446:Peptide Fragments / Q000494:pharmacology; D010974:Platelet Aggregation / Q000187:drug effects* / Q000502:physiology; D019038:Platelet Glycoprotein GPIb-IX Complex / Q000032:analysis; D044463:Receptor, PAR-1 / Q000502:physiology; D018179:Receptors, Thrombin / Q000378:metabolism* / Q000502:physiology*; D015398:Signal Transduction / Q000187:drug effects*; D013917:Thrombin / Q000378:metabolism; D013997:Time Factors
chemical_list: D009842:Oligopeptides; D019007:P-Selectin; D010446:Peptide Fragments; D019038:Platelet Glycoprotein GPIb-IX Complex; D044463:Receptor, PAR-1; D018179:Receptors, Thrombin; C455901:alanyl-tyrosyl-prolyl-glycyl-lysyl-phenylalanine; C082835:thrombin receptor peptide (42-47); D000244:Adenosine Diphosphate; D013917:Thrombin; D001081:Apyrase; C112908:protease-activated receptor 4