Tags: Protein.
Calcitonin (also known as thyrocalcitonin) is a 32-amino acid linear polypeptide hormone that is producedin humans primarily by the parafollicular cells (also known as C-cells) of the thyroid and in many other animals in the ultimobranchial body. It acts to reduce blood calcium (Ca2+) opposing the effects of parathyroid hormone (PTH). Calcitonin has been found in fish reptiles birds and mammals.