Sex related differences in serum gastrin concentrations and G- and D-cell populations of the gastric mucosa in guinea-pigs (experimental RIA and immunocytochemical study).

In the present study antral G-cells which secrete gastrin and antral and fundic D-cells which secret somatostatin, an inhibitor of gastric acid secretion were revealed immunocytochemically and the population size estimated along with serum gastrin levels in ten male and eight female guinea pigs. Serum gastrin, antral G-cells, antral D-cells and fundic D-cells were 41.90 +/- 6.10 SD pg/ml, 210 +/- 18.03 SD cells/cm, 128.20 +/- 17.64 SD cells/cm and 121 +/- 17.91 SD cells/cm respectively in males and 35 +/- 4.62 SD pg/ml, 176 +/- 13.80 SD cells/cm, 108.40 +/- 6.90 SD cells/cm and 106.8 +/- 6.50 SD cells/cm respectively in females. The differences in serum gastrin levels, antral G-cell population and antral D-cell population between the two sexes were statistically significant (P less than 0.05, P less than 0.001, P less than 0.01). It is possible that endogenous androgens induce a relative hyperplasia and endogenous oestrogens a relative hypoplasia of G-cells. Antral D-cell differences may reflect an adaptive hormonal mechanism to the possible different states of gastric secretory functions.