Nimodipine inhibits [3H]nitrobenzylthioinosine binding to the adenosine transporter in human brain.
The inhibition of [3H]nitrobenzylthioinosine ([3H]NBI) binding to human parietal cortex membranes by adenosine transport inhibitors, adenosine receptor agonists and antagonists and dihydropyridines was investigated. While the adenosine transport inhibitors inhibited [3H]NBI binding with Ki values in the low nanomolar range and the adenosine A1 receptor agonist, cyclopentyladenosine, with a Ki in the low micromolar range, no IC50 values could be obtained for the adenosine receptor antagonists at concentrations up to 100,000 nM. Among the dihydropyridines (+)-nimodipine was the most potent with a Ki of 201 +/- 55 nM. Inhibition of adenosine transport thus may contribute to the clinical effects of nimodipine in the central nervous system.
Deckert
J
J
Department of Psychiatry, University of Würzburg, Germany.
Bereznai
B
B
Hennemann
A
A
Gsell
W
W
Götz
M
M
Fritze
J
J
Riederer
P
P
D004095:Dihydropyridines / Q000378:metabolism / Q000494:pharmacology; D006801:Humans; D066298:In Vitro Techniques; D009553:Nimodipine / Q000494:pharmacology*; D010296:Parietal Lobe / Q000187:drug effects* / Q000378:metabolism; D018047:Receptors, Purinergic P1 / Q000378:metabolism*; D013868:Thioinosine / Q000031:analogs & derivatives* / Q000378:metabolism
D004095:Dihydropyridines; D018047:Receptors, Purinergic P1; D013868:Thioinosine; D009553:Nimodipine; C001789:4-nitrobenzylthioinosine