Barbiturique | EPFL Graph Search

Les barbituriques appartiennent à une famille médicamenteuse agissant comme dépresseurs du système nerveux central, et dont le spectre d'activité s'étend de l'effet sédatif à l'anesthésie. Certains sont aussi utilisés pour leurs vertus anticonvulsivantes. Tous sont dérivés de l'acide barbiturique et de ses homologues (acide thiobarbiturique, acide iminobarbiturique). Ils sont de nos jours beaucoup moins prescrits en raison de leurs effets indésirables, du risque d'abus, et de l'arrivée sur le marché de molécules à l'action comparable mais aux effets secondaires réduits et à la toxicité limitée (entre autres les benzodiazépines). En France, le phénobarbital (Gardénal) est encore indiqué et parfois prescrit, principalement par les neurologues pour ses propriétés antiépileptiques. Origine du nom Il existe plusieurs théories quant à l'origine du mot «barbiturique» :

la première fait remonter cette origine à la date de la synthèse de l'acide barbiturique par Adolf von Baeye

Modulation of VIP-Stimulated cAMP Formation by Excitatory Amino Acids in Mouse Cerebral Cortex

Pierre Magistretti

We have investigated the modulatory action of excitatory amino acids (EAA) on vasoactive intestinal polypeptide (VIP)-stimulated cAMP formation in mouse cerebral cortical slices. Glutamate and aspartate potentiate in a concentration-dependent manner the effect of VIP. In order to characterize the type of receptor involved, we have used three prototypical EAA receptor agonists, that is, kainate, N-methyl-d-aspartate (NMDA) and quisqualate. Kainate mimicked the effect of glutamate, NMDA was inactive and quisqualate displayed an inhibitory action. Furthermore, ibotenate also potentiated the effect of VIP on cAMP formation, while l-homocysteate exhibited an inhibitory action. Ibotenate was 4-fold more potent and 2.5 times more effective than glutamate. However, the effects of kainate and ibotenate were not additive, suggesting the activation of a common receptor. Thus, based on this metabotropic action, EAA can be categorized into the following classes: (i) those that potentiate the effect of VIP, such as glutamate, aspartate, kainate and ibotenate; (ii) those that inhibit the effect of VIP, such as l-homocysteate and quisqualate; and (iii) those that are ineffective, such as NMDA and d-homocysteate. The effects of glutamate or ibotenate on VIP-stimulated cAMP formation were completely inhibited by l-phosphoserine and only partially by kynurenate. In a low chloride medium, or in the presence of 8-(N,N-diethylamino) octyl-3,4,5-trimethoxybenzoate-hydrochloride (TMB-8), an inhibitor of calcium release from internal stores, EAA did not potentiate the effect of VIP, thus stressing the importance of these ions for the transduction of the glutamatergic signal. Our results indicate the existence of marked interactions between EAA and VIP on cAMP formation; the pharmacology of these interactions is, however, clearly distinct from the classical pharmacology of EAA which is mainly based on electrophysiological and binding studies.

1990

Modulation of VIP-Stimulated cAMP Formation by Excitatory Amino Acids in Mouse Cerebral Cortex

Pierre Magistretti

1990