Systemic administration of amylin increases bone mass, linear growth, and adiposity in adult male mice.

Amylin is a peptide hormone cosecreted with insulin from the pancreatic beta-cells that can act as an osteoblast mitogen and as an inhibitor of bone resorption. The effects on bone of its systemic administration are uncertain. The present study addresses this question in adult male mice that were given daily subcutaneous injections of amylin (10.5 microgram) or vehicle (n = 20 in each group) for 4 wk. Histomorphometric indices of bone formation increased 30-100% in the amylin-treated group, whereas resorption indices were reduced by approximately 70% (P < 0.005 for all indices). Total bone volume in the proximal tibia was 13.5 +/- 1.4% in control animals and 23.0 +/- 2.0% in those receiving amylin (P = 0.0005). Cortical width, tibial growth plate width, tibial length, body weight, and fat mass were all increased in the amylin-treated group. It is concluded that systemic administration of amylin increases skeletal mass and linear bone growth. This peptide has potential as a therapy for osteoporosis if its bone effects can be dissociated from those on soft tissue mass.