Evaluation of the antiplatelet effects of cilostazol, a phosphodiesterase 3 inhibitor, by VASP phosphorylation and platelet aggregation.
BACKGROUND
Cilostazol, a phosphodiesterase 3 inhibitor, is an antiplatelet drug that is widely used for preventing cardiovascular events, although, to date, there are few methods for evaluating its effects.


RESULTS
Blood samples were taken at baseline and at 3 and 12 h in 10 healthy male subjects after 100 mg cilostazol intake. Each sample was examined by Western blot for phosphorylation levels of vasodilator-stimulated phosphoprotein (VASP), an abundant cAMP-dependent kinase substrate in platelets, and by the optical aggregometer for ADP- and collagen-induced aggregation, before and after 8 nmol/L prostaglandin E(1) (PGE(1)) treatment. Cilostazol intake did not affect VASP phosphorylation levels or the maximal aggregation rates without PGE(1) treatment. However, cilostazol intake apparently enhanced PGE(1)-induced VASP phosphorylation and PGE(1)-mediated reduction of ADP-and collagen-induced maximal aggregation rates. Levels of VASP phosphorylated at Ser157 were correlated and the maximal aggregation rates induced by ADP were inversely correlated with cilostazol concentrations in the plasma.


CONCLUSIONS
The antiplatelet effects of cilostazol intake could be evaluated by measuring VASP phosphorylation levels and maximal aggregation rates in platelets by ex vivo treatment with a low concentration of PGE(1).
Yamamoto
Hiromi
H
Department of Cardiovascular Medicine, Graduate School of Medicine, Kyoto University, Honmachi, Sakyo-ku, Kyoto, Japan.
Takahashi
Kanako
K
Watanabe
Haruyo
H
Yoshikawa
Yuka
Y
Shirakawa
Ryutaro
R
Higashi
Tomohito
T
Kawato
Mitsunori
M
Ikeda
Tomoyuki
T
Tabuchi
Arata
A
Morimoto
Takeshi
T
Kita
Toru
T
Horiuchi
Hisanori
H
D000328:Adult; D000527:Alprostadil / Q000494:pharmacology; D001792:Blood Platelets / Q000378:metabolism*; D015815:Cell Adhesion Molecules / Q000378:metabolism*; D000077407:Cilostazol; D006801:Humans; D008297:Male; D008840:Microfilament Proteins / Q000378:metabolism*; D008875:Middle Aged; D058987:Phosphodiesterase 3 Inhibitors; D010750:Phosphoproteins / Q000378:metabolism*; D010766:Phosphorylation / Q000187:drug effects; D010974:Platelet Aggregation / Q000187:drug effects*; D010975:Platelet Aggregation Inhibitors / Q000008:administration & dosage*; D013777:Tetrazoles / Q000008:administration & dosage*; D000098662:Vasodilator-Stimulated Phosphoprotein
D015815:Cell Adhesion Molecules; D008840:Microfilament Proteins; D058987:Phosphodiesterase 3 Inhibitors; D010750:Phosphoproteins; D010975:Platelet Aggregation Inhibitors; D013777:Tetrazoles; D000098662:Vasodilator-Stimulated Phosphoprotein; D000527:Alprostadil; D000077407:Cilostazol