ISLET AMYLOID POLYPEPTIDE IN PSAMMOMYS-OBESUS - LACK OF CORRELATION BETWEEN INSULIN-RESISTANCE AND PLASMA IAPP LEVELS

Sand rats (Psammomys obesus) develop insulin resistance and diabetes w hen given a standard laboratory diet. We have examined the presence of islet amyloid polypeptide (IAPP), or amylin, in these animals. IAPP i s present in the beta-cells of pancreatic islets, its localization and intensity of immuno-reactivity are, thus, similar to that of insulin. In insulin resistant Psammomys obesus, insulin and IAPP immuno-reacti vity in pancreas are markedly decreased, plasma insulin levels are 20- fold higher than in controls but IAPP levels are not different from th ose of normal animals. Therefore, insulin resistance in Psammomys obes us does not appear to result from an elevated plasma IAPP level nor fr om development of amyloid deposits.