Quantitation of gastrin and somatostatin cell populations in the antral mucosa of the rat. Comparative distribution and evolution through different life stages.

Total antral gastrin and somatostatin cell populations as well as their relative distribution pattern throughout the antrum were studied in rats with advancing age from birth time to old age. Both endocrine cell populations were estimated, after staining by immunoperoxidase technique, with a quantitative method using serial parallel strips from entire stomachs. Gastrin cells were regularly found at less than 1 h of post-natal life, but were few in number (447 +/- 82) cells. Somatostatin cells, not seen at birth, were observed in all rats at seven post-natal days; then they increased in number less rapidly but more regularly than gastrin cells. During the normal adult period, corrected gastrin cell population corresponds to about 330,000-500,000 cells and corrected somatostatin cell populations to about 130,000-200,000 cells. For the whole antrum the ratio of gastrin cell to somatostatin cell populations decreases through the rat life from 6.5 at 7 days to 1.5 in old age with a stable value, 2.5, during adult period. Examination of the topographical distribution throughout the antrum of these two populations shows that, strip per strip, their numerical ratio varies. Homogeneous values for the latter occur in the middle part of antrum and, as rule, in each group they reflect the mean value calculated for the whole of the antrum.