RESUMO
A series of novel 6-(4-benzylpiperazin-1-yl)benzodioxanes were prepared and screened at selected dopamine receptor subtypes. 6-(4-[4-Chlorobenzyl]piperazin-1-yl)benzodioxane (2d) had high affinity and selectivity for the D(4) dopamine receptor subtype and was identified as a D(4) antagonist via its attenuation of dopamine-induced GTPgamma(35)S binding at the D(4) receptor.
Assuntos
Dioxanos/metabolismo , Antagonistas de Dopamina/química , Antagonistas de Dopamina/metabolismo , Ligantes , Piperazinas/metabolismo , Receptores de Dopamina D2/metabolismo , Animais , Células CHO , Cricetinae , Dioxanos/química , Dioxanos/farmacologia , Antagonistas de Dopamina/farmacologia , Antagonistas dos Receptores de Dopamina D2 , Avaliação Pré-Clínica de Medicamentos , Guanosina 5'-O-(3-Tiotrifosfato)/metabolismo , Piperazinas/química , Piperazinas/farmacologia , Primatas , Receptores de Dopamina D2/genética , Receptores de Dopamina D4 , Proteínas Recombinantes/genética , Proteínas Recombinantes/metabolismo , Relação Estrutura-AtividadeRESUMO
Both the antiepileptic, carbamazepine, and the N-methyl-D-aspartate receptor antagonist, dizocilpine, have shown preclinical efficacy against behavioral and toxic effects of cocaine. Nonetheless, side effects or toxicity of these compounds either alone or in conjunction with cocaine are problematic. 5-Aminocarbonyl-10,11-dihydro-5h-dibenzo[a,d]cyclohepten-5,1 0-imine (ADCI), a molecular hybrid of these compounds, has been shown to have a broad anticonvulsant profile with a good protective index (behavioral TD50/anticonvulsant ED50). In male Swiss Webster mice, ADCI and dizocilpine produced dose-dependent protection against the convulsant effects of cocaine that were insensitive to carbamazepine. However, in contrast to dizocilpine, ADCI did not produce behavioral impairment on the inverted screen test demonstrating a protective index of greater than 15; the protective index for dizocilpine was 1.2. All three compounds attenuated the locomotor stimulant effects of cocaine without significantly decreasing locomotor activity on their own, although the cocaine antagonism was not always dose dependent. Only dizocilpine increased spontaneous locomotor activity when given alone and augmented the locomotor stimulant effects of cocaine. The results confirm the novel anticonvulsant activity of ADCI and its lack of phencyclidine-like behavioral side effects. The data also suggest a modest blocking action of these compounds against the locomotor stimulatory effects of cocaine.