Immunohistochemical Study of Endocrine Cells in the Stomach and Small Intestine of the Lion (Panthera leo)

The distribution and relative frequency of gastrointestinal endocrine cells were investigated in the stomach and small intestine (duodenum and jejunum) of a lion (Panthera leo). The present study was an immunohistochemical investigation of endocrine cells showing immunoreactivity for serotonin, gastrin, or cholecystokinin (CCK). Serotonin-immunoreactive (IR) cells were detected throughout the gastrointestinal tract with the highest frequency in the duodenum. Gastrin-IR cells were numerous in the pyloric region of the stomach and moderate numbers were also seen in the duodenum and jejunum. Moderate numbers of CCK-IR cells were only detected in the duodenum and jejunum.