[Cytologic demonstration of immunoreactivity characteristic of adenopituitary peptides in the digestive epithelium of the rat and man].

Using immunoperoxidase techniques, the possible localization of pituitary regulatory peptides in fundic, antral and duodenal mucosae was investigated in both rat and man. All results obtained were similar in the two species. No glycopeptide (FSH, LH, TSH) was detected in the digestive tract. With different antisera directed against beta-lipotropin, alpha-MSH, beta-MSH, endorphins, ACTH 1-24, ACTH 17-39, a positive reaction was only obtained in the antral mucosae with an antiserum specific for the synthetic fragment 17-39 of ACTH. However neither the common precursor, proopiomelanocortin, nor the complete sequence of ACTH seem to be present in endocrine cells of the digestive tract. On the other hand, three antisera, directed against human growth hormone (GH), visualized numerous endocrine cells scattered in the glandular epithelium of the fundic and antral mucosae. Most cells were identified as ECL type in the gastric mucosae. Others are probably of the gastrin cell type in the antral mucosa, since these cells could be visualized on adjacent sections either with the antiserum against GH, or with a specific antiserum for gastrin.