The existence of argyrophilic endocrine cells in the digestive system of snake eels (Pisodonophis boro, Hamilton, 1822)

Abstract

The existence of the argyrophilic endocrine cells (AEC) of the digestive system in Pisodonophis boro (Hamilton, 1822), an economically important fish, was investigated for the first time. The existence of AEC was clearly detected along the digestive system, except for the posterior intestine by the Grumelius silver staining method. Two types of AEC (closed-type cell and open-type cell) were classified and observed in the mucosal layer. The closed-type cell was small and spherical in shape, whereas the open-type cell was triangular or elongated. The AECs in the stomach were detected in both the mucosal layer and the gastric gland, which were higher than that in the esophagus. The highest number of AEC was observed in the anterior intestine, but it was not observed in the posterior intestine. In addition, several granules in the hepatocyte and some cells in Langerhan’s islets in the pancreas were positively reacted with this method. The results indicated that the digestive tract especially the anterior intestine might be the main site of AEC relating to the production of the digestive hormones.