| Research Abstract |
Islet amyloid polypeptide(IAPP/amylin) is a 37 amino acid long peptide, being a major component of islet amyloid in non-insulin-dependent diabetes mellitus(NIDDM) and insulinoma. To delineate the pathophysiological significance of IAPP in NIDDM, we studied tissue content, plasma level, gene expression, response to physiological stimulation and immunohistochemical localization of the peptide in diabetics and rat models of diabetes. We also clarified molecular forms of the peptide in the pancreas, gastrointestinal tract and plasma from mammals that form pancreatic amyloid(human and cat) and mammals that do not form it(rat and mouse). Eleven of thirteen insulinomas had both immunoreactivities for IAPP and insulin, but other two had only insulin-immunoreactivity. Amyloid deposits were noted in 5 insulinomas whose clinical features will be presented. In addition, we report pathological features of amyloid in NIDDM and the amyloid in a gastrinoma. Islet amyloid deposition might be a secondary manifestation of disordered islet function, although we can not exclude that amyloid deposits intensify islet dysfunction and may contribute to the progression of NIDDM.
|
