Gastric secretory function in the developing human stomach.

Little data exists regarding the activity of gastric parietal cells in the very immature infant. Therefore we have examined the developing human stomach for the presence and location of parietal cells, using both standard histological methods and antibodies to the H+/K+ ATPase (proton pump) and intrinsic factor, in 35 fetuses (ranging from 13-28 weeks) and in five infants (2-21 weeks). Parietal cell activity was noted in the body, antrum and pyloric regions in all the fetal specimens examined. However, this activity was much more limited in the infant specimens. We have noted that from the end of the first trimester parietal cells are present in a mature, functional form with the potential to secrete both gastric acid and intrinsic factor.