抄録
It has been reported that application of glutamate into the rat stomach induces excitation of the gastric branch of the vagus nerve and activates specific brain loci. Since a specific blocker for serotonin receptor type 3 (SR3) inhibited the above excitation, and no report for the distribution of SR3-containing cells in the gastric mucosa was available, we examined the distribution of SR3 and serotonin (5-hydroxytryptamine, 5-HT) within the gastric and intestine mucosae. For SR3, prominent immunoreactivity was localized in the neck region of gastric glands. SR3-immunoreactive cells were irregular in shape, which were different population from mucous neck cells. A scattered population of 5-HT-immunoreactive cells was localized within the mucous epithelium and the basal region of the gastric glands. By contrast, no-SR3-immunoreactive cells were localized within the mucous epithelium and glandular components of the duodenum, whereas 5-HT-immunoreactive cells that were probably typical intestinal endocrine cells were frequently seen within its mucous membrane. Thus, it is very likely that the novel distributional pattern of 5-HT- and SR3-producing cells demonstrated in this study plays a crucial role for glutamate signaling in the gastric mucosa. The further characterization of these cells, together with other cell types related to the glutamate signaling, will be presented, and their physiological significance will be discussed. [J Physiol Sci. 2008;58 Suppl:S27]
