Immunohistochemical study of the gastrointestinal endocrine cells in the Korean aucha perch

Abstract

The regional distribution and relative frequency of neurohormonal peptides‐producing cells were demonstrated in the gastrointestinal (GI) tract of the Korean aucha perch Coreoperca herzi, using 10 types of specific antisera raised against mammalian regulatory peptides. The GI tract was divided into four portions: stomach, gastro‐intestinal junction, and small and large intestine. Most of the immunoreactive (IR) cells were in the mucosal epithelium and they were generally spindle shaped with a long cytoplasmic process. In addition, ovoid cells were found in the gastric regions. Serotonin‐, somatostatin‐, glucagon‐, cholecystokinin‐8 (CCK‐8)‐ and pancreatic polypeptide (PP)‐IR cells were observed with various relative frequencies. No chromogranin A‐, secretin‐, vasoactive intestinal peptide‐, substance P‐ or bombesin‐IR cells, however, were found. Serotonin‐IR cells occurred throughout the GI tract and were the most numerous. Somatostatin‐IR cells were restricted to the stomach and gastro‐intestinal junction in numerous and moderate frequencies, respectively, but small numbers of glucagon‐IR cells were restricted to the small intestine. Numerous CCK‐8‐IR cells were found in the small intestine but variable numbers of PP‐IR cells occurred throughout the GI tract except for the large intestine. In general the distribution and relative frequency of these IR cells correspond well to previous reports in teleosts but there are some difference in this species.