AMYLIN IN BONE CONSERVATION - CURRENT EVIDENCE AND HYPOTHETICAL CONSIDERATIONS

Amylin, a 37-amino-acid long single-chain polypeptide, is structurally homologous to calcitonin and calcitonin gene-related peptide (CGRP). The peptide is secreted from pancreatic beta cells and is thought to h ave an anti-insulin action. Here, we review the recently described eff ects of amylin on calcium homeostasis and discuss its possible role in bone conservation. Amylin is a potent hypocalcemic and antiresorptive peptide. Studies using isolated osteoclasts have revealed that amylin inhibits cell motility (Q effect), without affecting cell spread area or elevating cytosolic [Ca2+]. Thus, amylin action is similar to that of calcitonin, but lower in potency. Lower circulating concentrations of amylin in type-1 diabetes may cause the bone loss associated with this condition.