Islet amyloid polypeptide
Islet amyloid polypeptide coded for by the IAPP gene is processed from its coded 89 amino acids and cosecreted with insulin (and C-peptide) as a 37 amino acid hormone. It selectively inhibits insulin-stimulated glucose utilization and glycogen deposition in muscle. It delays gastric emptying. The glucagonostatic effect is restricted to meal-related glucagon secretion, and glucagon secretion and glucagon action during hypoglycaemia is preserved. A net weight loss can occur which may be of benefit in obesity as leptin responsiveness is restored by its actions, so analogues such as pramlintide are under development. It is structurally related to calcitonin. The processing of the protein can result in amyloid deposition in the islets as characteristic in type 2 diabetes and insulinomas. The variations in the 8-37 region of human islet amyloid polypeptide explain most of its amyloidogenic properties.
- ↑ Roth JD, Roland BL, Cole RL, Trevaskis JL, Weyer C, Koda JE, Anderson CM, Parkes DG, Baron AD. Leptin responsiveness restored by amylin agonism in diet-induced obesity: evidence from nonclinical and clinical studies. Proceedings of the National Academy of Sciences of the United States of America. 2008 May 20; 105(20):7257-62.(Link to article – subscription may be required.)
- ↑ Gilead S, Gazit E. The role of the 14-20 domain of the islet amyloid polypeptide in amyloid formation. Experimental diabetes research. 2008; 2008:256954.(Link to article – subscription may be required.)