Regional differences in the distribution of gastrin-, somatostatin-, and serotonin-immunoreactive basal granulated cells in the rat stomach: A quantitative analysis using antibodies against protein gene product 9.5 and gastric mucins

In the cardia, corpus, and pyloric antrum of the rat stomach fixed with antibodies against the gastric mucins localized in the pyloric antrum and cardia (RGM 22, RGM 26), the density of gastrin-, somatostatin-, and serotonin-immunoreactive basal granulated cells was represented as a percentage of the total number of basal granulated cells immunolabelled with the antibody against protein gene product (PGP) 9.5. In the pyloric antrum, RGM 22- and RGM 26-immunoreactive mucous cells were found in the distal 5 to 6 mm of the stomach, and in the cardia, they were found only in the proximal 4 to 6 pits of the stomach. In the cardia and corpus, the population of somatostatin-and serotonin-immunoreactive basal granulated cells accounted for 24.0-29.7% and 21.7-22.8% of the total basal granulated cells demonstrated with PGP 9.5 antibody, respectively. Tn the pyloric antrum, the ratio of somatostatin and serotonin cells increased to 48.2% and 42.8%, respectively, and the population of gastrin cells was 63.9% of the total basal granulated cells. In the three regions examined, the ratio of somatostatin cells was slightly higher than that of serotonin cells, and there was a tendency for the ratio of both kinds of cells to increase toward the more distal regions of the stomach. In the pyloric antrum, the ratio of somatostatin and serotonin cells was about twice higher than that of somatostatin and serotonin cells in the cardia and corpus. The present quantitative examination made it possible to perform a numerical analysis of basal granulated cells in the different areas of the rat stomach, and could be an indication of topographic difference in the gastric functions.