Parathyroid Hormone (1-34) (human) (trifluoroacetate salt)

Parathyroid hormone (PTH) (1-34) is an N-terminal fragment of PTH that regulates bone remodeling. It is a PTH receptor agonist that binds to the PTH1 receptor (IC50 = 2 nM) and increases cAMP accumulation (IC50 = 0.22 pM) in HEK293 cells expressing human PTH1. PTH (1-34) also stimulates cAMP accumulation in Saos-2 human osteoblast-like cells (IC50 = 0.38 nM) and bone resorption from neonatal mouse calvariae in vitro. In vivo, PTH (1-34) (40 µg/kg per day) increases bone mass in an ovariectomized adult rat model of postmenopausal osteoporosis. It also increases proteoglycan content and inhibits articular cartilage degeneration in knee joints in a mouse model of injury-induced osteoarthritis when administered at a dose of 40 µg/kg per day immediately following injury. Formulations containing PTH (1-34) have been used in the treatment of osteoporosis in men and postmenopausal women who are at high risk for fracture.