Oral prostaglandin E2 influences the enterochromaffin-like and somatostatin cell populations in the oxyntic mucosa of the rat.

Our aim was to study the effects of long-term oral administration of different doses of prostaglandin E2 (PGE2) and of a synthetic analogue on the endocrine cells and on selected epithelial cells of the rat oxyntic mucosa. The endocrine cells were visualized by immunohistochemical staining and by the Sevier-Munger method. Quantification of the mucosal cells was performed at a light-microscopic level using stereological methods. The highest dose of 15-R-15-methylprostaglandin E2 (MePGE2) increased the total volume of enterochromaffin-like (ECL) cell profiles whereas no changes were observed after treatment with PGE2. On the other hand, the total mucosal volume of chromogranin A-immunoreactive cells was significantly reduced by both doses of natural PGE2. The highest dose of PGE2 increased the total volume of somatostatin-immunoreactive cells. The serotonin-immunoreactive cells were very few and unaffected by treatments. E2 prostaglandins induced hyperplasia and hypertrophy of epithelial cells. A selective trophic action on the mucous but not on the parietal cells was observed. The area of the parietal cells was increased in rats treated with the analogue. The gastric acid content was increased in rats treated with the highest doses of E2 prostaglandins. The plasma level of somatostatin was significantly increased in rats given MePGE2 and the highest dose of PGE2. The cell population of chromogranin A-immunoreactive cells did not reach the levels of the NECL cells.(ABSTRACT TRUNCATED AT 250 WORDS)