Polypeptide hormones secreted by the parathyroid glands， which promote release of calcium from bone to extracellular fluid by activating osteoblasts and inhibiting osteoclasts， indirectly promote increased intestinal absorption of calcium， and promote renal tubular reabsorption of calcium and increased renal excretion of phosphates. It is a major regulator of bone metabolism. Secretion of parathyroid hormone increases when the level of calcium in the extracellular fluid is low. Its action is opposed by calcitonin.
PTH （7-34）， which is a PTH/PTHrP receptor antagonist， can stimulate hair growth and epidermal proliferation in mice.
Lyophilized Parathyrin although stable at room temperature for 3 weeks， should be stored desiccated below -18℃. Upon reconstitution PTH should be stored at 4℃ between 2-7 days and for future use below -18℃.
For long term storage it is recommended to add a carrier protein （0.1% HSA or BSA）.
Please prevent freeze-thaw cycles.
