Parathyroid Hormone An Anabolic Treatment for Osteoporosis.

Abstract

Osteoporosis is a disease characterised by low bone mass, structural deterioration of bone and increased risk of fracture. The prevalence, and cost, of osteoporosis is increasing dramatically with our ageing population and the World Health Organization now considers it to be the second-leading healthcare problem. All currently approved therapies for osteoporosis (eg., estrogen, bisphosphonates, calcitonin and selective estrogen receptor modulators) are anti-resorptive agents that act on osteoclasts to prevent further bone loss. A new class of bone anabolic agent capable of building mechanically strong new bone in patients with established osteoporosis is in development. While the parathyroid hormone (PTH) is classically considered to be a bone catabolic agent, when delivered intermittently at low doses PTH potently stimulates cortical and trabecular bone growth in animals humans. The native hPTH-(1-84) and its osteogenic fragment, hPTH-(1-34), have already entered Phase III clinical trials. Understanding the mechanism of PTH's osteogenic actions has led to the development of smaller PTH analogues which can also build mechanically normal bone in osteopenic rats. These new PTH analogues are promising candidates for treating osteoporosis in humans as they are as efficacious as hPTH-(1-84) and hPTH-(1-34), but there is evidence that they may have considerably less ability to induce hypercalcemia, the major side effect of PTH therapy. In addition to treating osteoporosis, PTHs may be used to promote fracture healing, to restore bone loss in immobilized patients, or following excessive glucocorticoid or prolonged spaceflight, and to treat psoriasis.

Nano-fibrous scaffold for controlled delivery of recombinant human PDGF-BB

“…Owing to the rapid advances in recombinant technology and the availability of large scale manufacturing of cytokines and growth factors, many recent tissue engineering strategies have turned to the use of specific growth factors to stimulate cellular activity in vitro and for improved functional neotissue formation in vivo [2][3][4][5]. Importantly, the delivery mode appears to be critical for the application of these factors in tissue engineering [6][7][8].…”

Systemic delivery of parathyroid hormone (1-34) using inhalation dry powders in rats

“…Its 1 to 34 N-terminal fragment (PTH) exhibits full biological activity and has been shown effective for the treatment of postmenopausal osteoporosis in Phase III clinical trials. 1,2 A major challenge that remains in PTH therapy consists in finding a noninvasive alternative to the daily sc injections. Oral PTH delivery showed a bioavailability of 5% and 2.1% relative to sc administration in rats and monkeys, respectively.…”

The Anti-osteoporotic Effect of Aqueous Extracts of Gastrodiae Rhizoma In Vitro and In Vivo

“…In addition, GR extracts enhance the osteoblasts proliferation, differentiation and activity, and they inhibit the osteoclastogenesis and activity of osteoclasts. Although the efficacy was slighter than that of alendronate on the inhibition of trabecular bone loss, it is expected that GR extracts will be promising as a new anti-osteoporotic agents for prevent the fracture induced in osteoporotic patients because natural herbal medicine origin GR extracts will be dose not show serious side effects especially the problem in upper alimentary irritation of bisphosphonate, 42) and hypocalcaemia and hormone disturbance of parathyroid hormone analogs.…”