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 μg/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.
- Animal models
- Bone density technology
- Osteoporosis therapy
ASJC Scopus subject areas
- Endocrinology, Diabetes and Metabolism
- Orthopedics and Sports Medicine