Seven canine pancreatic endocrine tumors were evaluated immunohistochemically for the presence of islet amyloid polypeptide (IAPP), calcitonin gene-related peptide (CGRP), and several other pancreatic hormones. Four tumors contained cells with IAPP immunoreactivity, and four had cells with CGRP immunoreactivity. IAPP and CGRP immunoreactivities were localized to distinctly different cell populations in three tumors in which both peptides were detected; however, IAPP immunoreactivity consistently was found in cells that also contained insulin immunoreactivity. Amyloid deposits, which were found in three of the seven tumors, showed strong immunoreactivity with antiserum against IAPP and weaker immunoreactivity with antiserum to CGRP. These results indicate that amyloid deposits in canine pancreatic endocrine tumors are likely derived from IAPP, as is amyloid found in human pancreatic endocrine tumors and pancreatic islet amyloid in aged and diabetic persons and cats.
Bibliographical noteFunding Information:
The authors thank K. Jordan for performing the immunoperoxidase staining. This work was supported by a grant from the National Institute of Diabetes and Digestive and Kidney Diseases (R01-DK-36734), by the Swedish Medical Research Council (Project No. 5941), the Research Fund of King Gustaf V, the Nordic Insulin Fund, and Louis-Hansen's Memorial Fund. Antiserum against human calcitonin gene-related peptide was donated by Dr. Bernie Roos (University of Washington, Pullman, WA).
- islet amyloid polypeptide
- pancreatic neoplasms