vasoactive-intestinal-peptide has been researched along with bicuculline-methobromide* in 1 studies
1 other study(ies) available for vasoactive-intestinal-peptide and bicuculline-methobromide
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GABAB receptor-mediated enhancement of vasoactive intestinal peptide-stimulated cyclic AMP production in slices of rat cerebral cortex.
Basal and vasoactive intestinal peptide (VIP)-stimulated accumulations of cyclic AMP were measured in slices of rat cerebral cortex. Neither gamma-aminobutyric acid (GABA) nor the selective GABAB receptor agonist (-)-baclofen stimulated basal cyclic AMP accumulation, whereas VIP caused a large dose-dependent increase in cyclic AMP levels. However, in the presence of 100 microM (-)-baclofen, the effects of VIP on cyclic AMP accumulation were significantly enhanced, with the responses to 1 microM and 10 microM VIP being approximately doubled. The enhancing effects of (-)-baclofen was dose related (1-1,000 microM), but an enhancing effect was not observed with 100 microM (+)-baclofen. In the presence of the GABA uptake inhibitor nipecotic acid (1 mM), GABA caused a similar dose-related enhancement of the VIP response. The ability of either GABA or (-)-baclofen to augment VIP-stimulated production of cyclic AMP was not mimicked by the GABAA, agonists isoguvacine and 4,5,6,7-tetrahydroisoxazolo[5,4-c]pyridin-3-ol (THIP) and was not antagonized by the GABAA antagonist bicuculline. The putative GABAB antagonist 5-aminovaleric acid (1 mM) significantly reduced the effect of (-)-baclofen. The ability of (-)-baclofen to enhance VIP-stimulated accumulation of cyclic AMP was observed in slices of rat cerebral cortex, hippocampus, and hypothalamus. These results indicate that GABA and (-)-baclofen can enhance VIP-stimulated accumulation of cyclic AMP in rat brain slices via an interaction with specific GABAB receptors. Topics: Amino Acids; Amino Acids, Neutral; Animals; Baclofen; Bicuculline; Cerebral Cortex; Cyclic AMP; Dose-Response Relationship, Drug; Drug Synergism; gamma-Aminobutyric Acid; Isoxazoles; Male; Rats; Rats, Inbred Strains; Receptors, GABA-A; Vasoactive Intestinal Peptide | 1986 |