Premium
Characterization of P2x1 purinoreceptors on rat platelets: effect of clopidogrel
Author(s) -
Savi Pierre,
Bornia Josette,
Salel Veronique,
Delfaud Marianne,
Herbert JeanMarc
Publication year - 1997
Publication title -
british journal of haematology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.907
H-Index - 186
eISSN - 1365-2141
pISSN - 0007-1048
DOI - 10.1046/j.1365-2141.1997.3133126.x
Subject(s) - platelet , gtp' , adenosine diphosphate , thienopyridine , population , chemistry , ex vivo , adenylyl cyclase , biochemistry , alpha (finance) , adenylate kinase , clopidogrel , receptor , biophysics , biology , in vitro , medicine , enzyme , platelet aggregation , aspirin , environmental health , construct validity , nursing , patient satisfaction
This study aimed to determine the binding characteristics of [ 3 H]α,β‐Me‐ATP, a specific ligand of the P2x1 receptors to rat platelets, and to investigate the effect of clopidogrel, a thienopyridine compound which has been found to selectively inhibit ADP‐induced platelet aggregation and adenylyl cyclase ex vivo . Binding of [ 3 H]α,β‐Me‐ATP to rat platelets was time‐dependent and saturable. Scatchard analysis of the saturation binding data indicated that [ 3 H]α,β‐Me‐ATP bound to one population of specific binding sites with high affinity ( K D = 23.6 ± 1.6 n m ; B max = 690 ± 24 fmole/10 8 cells) ( n= 3). Unlabelled α,β‐Me‐ATP as well as 2‐MeS‐ADP and ADP competitively inhibited the specific binding of [ 3 H]α,β‐Me‐ATP with IC 50 values of 19.0 ± 6.6, 103 ± 20 and 1120 ± 80 n m respectively ( n= 3). Other nucleotide analogues such as ATP, ATP‐γS, UTP and GTP also antagonized [ 3 H]α,β‐Me‐ATP binding. When administered orally (10 mg/kg, p.o.), clopidogrel inhibited ADP‐ or 2‐MeS‐ADP‐induced platelet aggregation but did not affect the binding of [ 3 H]α,β‐Me‐ATP to rat platelets ex vivo. In vitro , α,β‐Me‐ATP did not induce the aggregation or shape change of rat platelets and did not interfere with ADP‐induced platelet aggregation.