Distribution of neuropeptides in endocrine and exocrine pancreas of long-legged buzzard (Buteo rufinus): An immunohistochemical study

This study aimed to determine the existence and distribution of certain neuropeptides in endocrine and exocrine pancreas of the long-legged buzzard by using immunohistochemical methods. SOM-14-, NPY- and CGRP-IR endocrine cells were determined in both central and peripheral regions in A-islets within the pancreas, while SP-IR endocrine cells were found only in the central region, and CCK-8- and galanin-IR endocrine cells were only detected in peripheral region. On the other hand, in B-islets; SP-, NPY- and CGRP-IR endocrine cells were determined in both central and peripheral regions, while SOM-14- CCK-8- and galanin-IR endocrine cells were found only in the peripheral region. In addition; SOM-14-, NPY-, CGRP-, CCK-8- and galanin-IR cells were also observed in exocrine pancreas. This distribution pattern in the pancreas of the long-legged buzzard demonstrates that neuropeptides perform their probable affects through endocrine and/or paracrine mechanisms. In conclusion, the existence and distribution of neuropeptides in the pancreas of long-legged buzzard have been introduced in this study for the first time and this bird species has also been found to differ from other types of avian species.

Research Highlights
► SOM-14, SP, NPY, CGRP, CCK-8 and galanin exists in A- and B-islet cells of pancreas.
► All except SP of peptides exists in exocrine pancreas with different frequencies.
► Results of this study in long-legged buzzard vary from other types of avian species.