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R Yui

Publications and source records attributed to R Yui.

22 records · Page 2Linked to original sources
PubMed1981

Evolutionary aspects of "brain-gut peptides": an immunohistochemical study.

Phylogeny of biogenic peptides and their source cells was studied by immunohistochemistry and electron microscopy. The distribution of the peptide containing neurons and paraneurons in the brain and in the gastroenteropancreatic endocrine system was depicted, especially in the bullfrog as the representative of deuterostomia and in the cockroach and some other insects as the representatives of protostomia. Stress was given to: (1) calcitonin-immunoreactive neurons in bullfrog hypothalamus and PP-reactive neurons in the cockroach protocerebrum as instances of transmissional-hormonal partition of a neuropeptide, (2) open-type endocrine cells in the gut structurally and functionally common to the protostomia and deuterostomia, and (3) phylogeny of the prohormones with special reference to big gastrin and proglucagon (glicentin).

Animals↗
PubMed1981

Immunohistochemical study of the pancreatic endocrine cells of the ray, Dasyatis akajei.

The pancreatic endocrine cells of the ray, Dasyatis akajei was studied by aldehyde-fuchsin-Masson-Goldner's staining and by immunohistochemical methods. The pancreatic endocrine cells of the ray do not form islets by represent the most primitive distribution among elasmobranchs, occupying the outer layer of the double-layered duct epithelium of the pancreas. The endocrine cells showed no evidence of reaching the duct lumen, i. e., they are closed in type. By the use of immunohistochemical techniques, insulin-, glucagon-, somatostatin-and pancreatic polypeptide (PP)-like immunoreactivities were detected in the endocrine cells. The PP-positive cells could not be differentiated from the somatostatin-immunoreactive cells, although the former were smaller in number. The possible reasons for this result were discussed. The present finding supports the view that those four peptides are essential regulatory substances of the endocrine system of the pancreas at a fairy early stage of vertebrate evolution.

Animals↗