Histological and immunohistochemical studies of the endocrine cells of the gastrointestinal mucosa of the toad (Bufo regularis)

Abstract

Using histological and immunhistochemical techniques, nine endocrine cell types were observed in the mucosa of the gastrointestinal tract of the toad, Bufo regularis, viz. enterochromaffin, somatostatin, glucagon, pancreatic polypeptide (PP), secretin, gastric inhibitory peptide (GIP), gastrin-C-terminal pentapeptide (GTPP), neurotensin and bombesin cells. The enterochromaffin cells were distributed throughout the gastrointestinal tract except the rectum. Somatostatin, glucagon, PP, secretin, GIP and GTPP cells were observed both in the stomach and in the small intestine. Neurotensin cells were seen only in the ileum and bombesin cells only in the pyloric and antral parts of the stomach. Immunostaining of consecutive sections did not reveal more than one polypeptide hormone in any of these cell types. It is concluded from the present results that the toad gastrointestinal mucosa contains endocrine cell types that are more or less homologous to those in the mammal alimentary tract, though some of them exhibit a different topographic distribution.

An immunohistochemical study of the endocrine cells in the gastrointestinal mucosa of the Caiman latirostris.

“…The absence of GIP-immunoreactive cells in the caiman intestine corroborates observations reported in the alligator (BUCHAN et al, 1983). However, the intestine of the grass lizzard (EL-SALHY and GRIMERIUS, 1981), the teleost fishes (FALKMER et al, 1980) and the cartilaginous fish (EL-SALHY, 1984) do contain GIPimmunoreactive cells. Pancreatic hormones of the alligator are reported to be more closely related to avian than mammalian species (BUCHAN et a!.,1983 ;LANCE et a!.,1984).…”

<b>IMMUNOCYTOCHEMICAL EVIDENCE FOR THE OCCURRENCE OF PY</b><b><b>Y, A NEWLY ISOLATED GUT POLYPEPTIDE, IN ENDOCRINE CELLS IN THE GUT OF AMPHIBIANS AND </b><b>REPTILES</b>¹</b>

“…The frequency and distribution of these three cell types in various parts of the alimentary canal of the toad and the grass lizard are given in Table 1. The description of PP and neurotensin-immunoreactive cells was similar to that given previously (2,3). PYY-immunoreactive cells were observed in the duodenum and ileum of both the toad and the grass lizard.…”

An Immunohistochemical Study of Endocrine Cells in the Alimentary Tract of the Red-bellied Frog, Bombina orientalis.

“…The red-bellied frog, Bombina orientalis, belonging to the order Anura is widely distributed in Korea and anatomical and histological structure of anuran amphibian was well identified in Bufo regularis [7]. Gastrointestinal endocrine cells dispersed in the epithelia and mucosal glands of the alimentary tract synthesize various kinds of the gastrointestinal hormones and play an important role in the physiological functions of the alimentary tract [2].…”