Role of 5-HT1B/D receptors in canine gastric accommodation: effect of sumatriptan and 5-HT1B/D receptor antagonists.

The 5-HT1B/D receptor agonist sumatriptan has been proposed to treat dyspeptic symptoms, because it facilitates gastric accommodation. It is unknown whether stimulation of 5-HT1B/D receptors is involved. Thus, in four conscious dogs, we compared the effects of sumatriptan alone or combined with N-[4-methoxy-3-(4-methyl-1-piperazinyl) phenyl]-2'-methyl-4'-(5-methyl-1,2,4-oxadiazol-3-yl)-[1,1-biphenyl]-4-carboxamide hydrocloride (GR-127935), N-[3-[3 (dimethylamino)-ethoxy]-4-methoxyphenyl]-2'-[methyl-4'-(5-methyl-1,2,4-oxadiazol-3-yl)]-[1,1-biphenyl]-4-carboxamide hydrocloride (SB-216641 hydrochloride), or 3-[4-(4-chloro-phenyl)piperazin-1-yl]-1,1-diphenyl-2-propanol hydrochloride (BRL-15572 hydrochloride) (respectively, nonselective 5-HT1B/D, selective 5-HT1B, and selective 5-HT1D receptor antagonists) on gastric accommodation to isobaric distensions performed with a barostat.

Role of tachykininergic and cholinergic pathways in modulating canine gastric tone and compliance in vivo.

Acetylcholine and tachykinins act as co-transmitters along excitatory pathways at different gut levels. Since cholinergic pathways are involved in maintaining gastric tone during fasting, our aim was to study the possible role of tachykininergic pathways in modulating canine gastric tone and compliance in vivo by using selective tachykinin receptor antagonists. In four fasting, conscious dogs, we characterized the pressure-volume relationship in the proximal stomach by using a barostat.