当前位置： SCI文献检索 > BIOCHEMICAL PHARMACOLOGY期刊下所有文献 > Role of adenosine uptake and metabolism by blood cells in the antiplatelet actions of dipyridamole, dilazep and nitrobenzylthioinosine.

Role of adenosine uptake and metabolism by blood cells in the antiplatelet actions of dipyridamole, dilazep and nitrobenzylthioinosine.

Abstract：

:Adenosine (Ado, 10 microM) did not inhibit ADP-induced human platelet aggregation in whole blood. However, if the blood was preincubated with dipyridamole (10 microM), a potent inhibitor of the erythrocytic nucleoside transport system (NTS), Ado acted as a strong inhibitor of platelet aggregation. Similarly, Ado inhibited platelet aggregation in whole blood in the presence of other potent NTS inhibitors, dilazep (1 microM) and p-nitrobenzylthioinosine (NBMPR, 1 microM). RA 233 (10 microM), an analog of dipyridamole which is a potent inhibitor of platelet cAMP phosphodiesterase (PDE), did not evoke the Ado effect in whole blood. However, in platelet-rich plasma (PRP), RA 233 potentiated strongly Ado-mediated inhibition, whereas dipyridamole, dilazep and NBMPR were without activity. 5'-Methylthioadenosine (MTA), an Ado receptor antagonist, reversed the inhibition produced by a nucleoside transport system inhibitor plus Ado in whole blood. Dipyridamole (10 microM), dilazep (1 microM) or NBMPR (1 microM) blocked [14C]Ado (10 microM) uptake by blood cells in whole blood, whereas RA 233 (10 microM) was not effective. The combination of 2'-deoxycoformycin (dCF, 5 microM), a tight-binding inhibitor of adenosine deaminase (ADA), plus 5-iodotubercidin (ITu, 10 microM), a potent inhibitor of adenosine kinase (Ado kinase), gave comparable Ado-mediated inhibition of platelet aggregation in whole blood as was obtained when the blood was pretreated with dilazep. These studies suggest that the in vivo antiplatelet actions of drugs such as dipyridamole and dilazep result from their abilities to block erythrocytic Ado uptake and subsequent metabolism, thus elevating the extracellular steady-state concentration of the physiologically occurring, antiplatelet agent, Ado.

journal_name

Biochem Pharmacol

journal_title

Biochemical pharmacology

authors

Dawicki DD,Agarwal KC,Parks RE Jr

doi

10.1016/0006-2952(85)90373-9

subject

Has Abstract

pub_date

1985-11-15 00:00:00

pages

3965-72

issue

eissn

0006-2952

issn

1873-2968

pii

0006-2952(85)90373-9

journal_volume

pub_type

杂志文章

在线工具

Role of adenosine uptake and metabolism by blood cells in the antiplatelet actions of dipyridamole, dilazep and nitrobenzylthioinosine.