Structure and properties
Polypeptide composed of 84 amino acids
Synthesis and release
Formation in the parathyroid glands
Effects
Bone resorption by activation of osteoclasts: increase in blood calcium levels Effect on kidney:
- Decrease in phosphate reabsorption: decrease in blood phosphate level.
- Decrease in calcium excretion: increase the level of calcium in the blood.
- Stimulation of vitamin D production
Effect on the intestine (lesser importance):
- Increased absorption of calcium: increase the level of calcium in the blood.
- Increased absorption of phosphate: increase the level of phosphate in the blood.
Mechanism of action
Interaction with membrane G protein-coupled receptors.
Substances and indications
- Teriparatide (Forsteo) is a fragment of parathyroid hormone (amino acids 1-34) and is used to treat osteoporosis
- Dihydrotachysterol (A.T. 10) shows similar effects to parathyroid hormone and is indicated for parathyroid insufficiency and pseudohypoparathyroidism.
- See also vitamin D3
Pathophysiology
Hypoparathyroidism and hyperparathyroidism.
