Amylin or Islet Amyloid Polypeptide (IAPP) is a 37-residue peptide hormone secreted by pancreatic β-cells at the same time as insulin (in a roughly 100:1 ratio). It was identified independently by two groups as the major component of diabetes-associated islet amyloid deposits in 1987.

Amylin's normal role in the body is unknown, although rodent amylin knockouts are known to fail to achieve the normal anorexia following food consumption. Because it is an amidated peptide, like many neuropeptides, it is believed to be responsible for the anorectic effect.

Amylin is also the name of a San Diego-based pharmaceutical company which began with the premise of using amylin as a hormone-replacement therapy for type II diabetics. Although it was unable to develop amylin for that purpose due to its amyloidogenicity, it did successfully market Symlin which uses the same strategy; and also markets Byetta, a completely different drug for diabetics.

References

1. Cooper GJ, Willis AC, Clark A, Turner RC, Sim RB, Reid KB. 1987. Purification and characterization of a peptide from amyloid-rich pancreases of type 2 diabetic patients. Proc Natl Acad Sci USA 84(23):8628–8632. PMID 3317417.
2. Westermark P, Wernstedt C, Wilander E, Hayden DW, O'Brien TD, Johnson KH. 1987. Amyloid fibrils in human insulinoma and islets of Langerhans of the diabetic cat are derived from a neuropeptide-like protein also present in normal islet cells. Proc Natl Acad Sci USA 84(11):3881-3885. PMID 3035556.
3. Amylin Pharmaceuticals, Inc
4. Amyloidosis in cats from Petdiabetes wiki.
5. Chronic Oxidative Stress as a Central Mechanism for Glucose Toxicity in Pancreatic Islet Beta Cells in Diabetes. JBC Vol. 279, Issue 41, 42351-42354, October 8, 2004

Peptide hormones