The effect of different calcium channel blockers was studied on basal and cocaine-inhibited [3H]dopamine uptake in rat striatal synaptosomes. Isradipine (dihydropyridine calcium antagonist) and diltiazem (L-type calcium antagonist) were devoid of effect on [3H]dopamine uptake, while flunarizine (T-type calcium antagonist) inhibited [3H]dopamine uptake. Flunarizine inhibition was competitive and the inhibitory curve was biphasic with a Hill coefficient of 2.1. The high Hill number suggested a mechanism of positive cooperativity between two sites. Flunarizine inhibition showed a complex interaction with cocaine inhibition. While flunarizine at low concentrations interacts with a distinct site, at higher concentrations it interacts with the same site as cocaine. The relevance of this finding for the potentiation by flunarizine of cocaine-induced dopamine release in vivo is discussed.

Devoto, P., Pani, L., Kuzmin, A., & DE MONTIS, M.G. (1991). Inhibition of [3H] dopamine uptake by flunarizine. EUROPEAN JOURNAL OF PHARMACOLOGY, 203(1), 67-69 [10.1016/0014-2999(91)90791-N].

Inhibition of [3H] dopamine uptake by flunarizine

DEVOTO, P.;DE MONTIS, M. G.
1991

Abstract

The effect of different calcium channel blockers was studied on basal and cocaine-inhibited [3H]dopamine uptake in rat striatal synaptosomes. Isradipine (dihydropyridine calcium antagonist) and diltiazem (L-type calcium antagonist) were devoid of effect on [3H]dopamine uptake, while flunarizine (T-type calcium antagonist) inhibited [3H]dopamine uptake. Flunarizine inhibition was competitive and the inhibitory curve was biphasic with a Hill coefficient of 2.1. The high Hill number suggested a mechanism of positive cooperativity between two sites. Flunarizine inhibition showed a complex interaction with cocaine inhibition. While flunarizine at low concentrations interacts with a distinct site, at higher concentrations it interacts with the same site as cocaine. The relevance of this finding for the potentiation by flunarizine of cocaine-induced dopamine release in vivo is discussed.
Devoto, P., Pani, L., Kuzmin, A., & DE MONTIS, M.G. (1991). Inhibition of [3H] dopamine uptake by flunarizine. EUROPEAN JOURNAL OF PHARMACOLOGY, 203(1), 67-69 [10.1016/0014-2999(91)90791-N].
File in questo prodotto:
Non ci sono file associati a questo prodotto.

I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.

Utilizza questo identificativo per citare o creare un link a questo documento: http://hdl.handle.net/11365/9694
 Attenzione

Attenzione! I dati visualizzati non sono stati sottoposti a validazione da parte dell'ateneo