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 have an anti-insulin action. Here, we review the recently described effects 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 [Ca(2+)]. 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.
Zaidi
M
M
Bone Research Unit, Division of Biochemical Medicine, St. George's Hospital Medical School, London SW 17 ORE, UK.
Shankar
V S
VS
Huang
C L
CL
Pazianas
M
M
Bloom
S R
SR