Amylin Coexisting With Peptide YY ( PYY ) and Amylin/ PYY Cells Correspond to Subpopulations of G

ABSTRACT

The distribution of amylin‐like substances was investigated by immunohistochemistry in the pancreas of the Japanese eel ( Anguilla japonica ). Amylin‐immunoreactive cells were observed in pancreatic islets. These immunostaining profiles were not observed by the preabsorption of the anti‐amylin serum with synthetic amylin, indicating that the serum specifically recognized eel amylin‐like peptide. Almost all amylin‐immunoreactive cells were immunopositive for peptide YY, suggesting that amylin and peptide YY co‐secreted from the islet cells might participate in the modulation of insulin and glucagon secretion in the pancreatic islets. In addition, weakly glucagon‐immunopositive cells, but not densely glucagon‐immunopositive cells, also corresponded to amylin‐immunoreactive cells. The subpopulation of glucagon‐immunoreactive and glucagon‐like peptide‐1‐immunoreactive cells was also immunopositive for peptide YY. These results suggest that amylin and peptide YY, and also presumably glucagon‐like peptide‐1, are co‐secreted from the amylin/peptide YY cells, and these three peptides modulate food intake through the central nervous system in addition to intrainsular functions.