Trophic effect of pentagastrin on normal and regenerating parietal cells. A light and electron microscopic study in rats.

Gastric mucosal wounds were produced by cauterization of the oxyntic gland area in adult rats. From the first postoperative day, one group of animals was given two daily subcutaneous injections of pentagastrin, 250 micrograms/kg body wt, dissolved in hydrolyzed gelatin. The remaining rats served as controls and were given saline in the gelatin. After 90 days of treatment the animals were killed and the gastric mucosa was prepared for light and electron microscopy. Using stereologic techniques, data on parietal cells were obtained from both normal and regenerating mucosas. Pentagastrin induced a 2.3-fold increase in the parietal cell volume density in the regenerating mucosa and a 1.3-fold increase in normal mucosa. However, pentagastrin did not affect the ultrastructure of the parietal cells. Thus, the well-known trophic effect of pentagastrin on the gastric mucosa was confirmed; however, the absence of ultrastructural changes in the parietal cells suggests that the target for its trophic effect is likely to be the progenitor cell population.