A Single Injection of the Anabolic Bone Agent, Parathyroid Hormone-Collagen Binding Domain (PTH-CBD), Results in Sustained Increases in Bone Mineral Density for up to 12 Months in Normal Female Mice
by Ponnapakkam, T.; Katikaneni, R.; Suda, H.; Miyata, S.; Matsushita, O.; Sakon, J.; Gensure, R. C.
Parathyroid hormone (PTH) is the most effective osteoporosis treatment, but it is only effective if administered by daily injections. We fused PTH(1-33) to a collagen binding domain (PTH-CBD) to extend its activity, and have shown an anabolic bone effect with monthly dosing. We tested the duration of action of this compound with different routes of administration. Normal young C57BL/6J mice received a single intraperitoneal injection of PTH-CBD (320 mu g/kg). PTH-CBD treated mice showed a 22.2 % increase in bone mineral density (BMD) at 6 months and 12.8 % increase at 12 months. When administered by subcutaneous injection, PTH-CBD again caused increases in BMD, 15.2 % at 6 months and 14.3 % at 12 months. Radiolabeled PTH-CBD was concentrated in bone and skin after either route of administration. We further investigated skin effects of PTH-CBD, and histological analysis revealed an apparent increase in anagen VI hair follicles. A single dose of PTH-CBD caused sustained increases in BMD by > 10 % for 1 year in normal mice, regardless of the route of administration, thus showing promise as a potential osteoporosis therapy.
- Journal
- Calcified Tissue International
- Volume
- 91
- Issue
- 3
- Year
- 2012
- Start Page
- 196-203
- URL
- https://dx.doi.org/10.1007/s00223-012-9626-1
- ISBN/ISSN
- 1432-0827; 0171-967X
- DOI
- 10.1007/s00223-012-9626-1