The regional distributions and relative frequencies of the gastrin, secretin and pancreatic polypeptide(PP)-immunoreactive cells in the gastrointestinal tract of the fetus(180 days of gestation) of Korean native goat were sutdied with immunohistochemical(ABC) methods. Gastrin-immunoreactive cells were detected in fundus, pylorus and duodenum and these cells were most predominant in pylorus. Secretin-immunoreactive cells were observed in pylorus, duodenum and ileum. PP-immunoreactive cells were restricted to fundus. These immunoreactive cells were situated in surfact epithelium and mucosal gland regions. The regional distribution and relative frequency of PP-immunoreactive cells was somewhat different to the adult Korean native goat. Immunoreactive cells in thesurface epithelial regions were open typed cells which were spindle shaped cells but closed typed cells which were round or/to spherical shaped cells were observed in the mucosal gland regions.

To investigate the regional distribution and relative frequency of the neurotensin-, pancreatic polypeptide(PP)- and gastrin/cholecystokinin(Gas/CCK)-immunoreactive cells in the gastrointestinal tract of the bullfrog(Rana catesbeiana) with developmental stages, group of bullfrogs subdivided into the tadpole withhindlegs, metamorphosed bullfrog with tail, 2 weeks after metamorphosed bullfrog and adult bullfrog, were stained by immunohistochemical methods(PAP methods). Neurotensin-immunoreactive cells were observed from the pylorus of the metamorphosed bullfrog with tail, but these cells were not detected after that periods. PP-immunoreactive cells were dectected from the adult bullfrog in the pylorus, duodenum and ileum. These cells were most predominant in the pylorus. Gas/CCK-immunoreactive cells were observed from the adult bullfrog in the pylorus. According to these results, most of immunoreactive cells in the gastrointestinal tract of the bullfrog were appeared after the complete metamorphosed periods, in which the complete differentiation of structure of gastrointestinal tract were occurred, and variable changes of the regional distribution and relative frequency with developmental stages were observed.