An immunohistochemical study on the distribution of endocrine cells in the digestive tract of gray goose (Anser anser)

Th e objective of this study was to investigate the morphology and the distribution of 5-hydroxytryptamine (5HT), somatostatin (SS), gastrin (Gas), glucagon (Glu), and substance P immunoreactive (IR) cells in the digestive tract of gray goose by the immunohistochemical streptavidin-peroxidase method. Th e samples were taken from 10 healthy adult gray geese. Th e results showed that 5 kinds of IR cells were mainly distributed between the mucous epithelium and intestinal gland. Th e number of 5-HT-IR cells was highest in the rectum and duodenum, but none were observed in the pylorus. SS-IR cells appeared in great numbers in the pylorus, duodenum, and cecum; however, they were not found in esophagus. Gas-IR cells were mainly distributed in the glandular stomach and jejunum. Glu-IR cells appeared in small numbers in the glandular stomach, duodenum, and jejunum, but were not detected in other tissues. Substance P-IR cells were located in the jejunum, cecum, and rectum. Analysis of the present study showed that the distribution and morphological features of these 5 diff erent endocrine cells were related to the feeding habits and metabolism in the digestive tract of the gray goose.