[kal-si-toh-nin] 
| a polypeptide hormone that participates in the regulation of calcium levels in vertebrates by inhibiting loss of calcium from bone to the blood. |
| cal·ci·to·nin (kāl'sĭ-tō'nĭn) n. A peptide hormone, produced by the thyroid gland in humans, that lowers plasma calcium and phosphate levels without augmenting calcium accretion. Also called thyrocalcitonin. [calci- + ton(e) + -in.] |
calcitonin cal·ci·to·nin (kāl'sĭ-tō'nĭn)
n.
A peptide hormone, produced by the thyroid gland in humans, that acts to lower plasma calcium and phosphate levels without augmenting calcium accretion. Also called thyrocalcitonin.
| calcitonin (kāl'sĭ-tō'nĭn) Pronunciation Key
A peptide hormone secreted by the thyroid gland that stimulates bone formation and lowers blood calcium and phosphate levels. |
calcitonin
a protein hormone secreted in humans and other mammals by parafollicular cells in the thyroid gland, and in birds, fishes, and other nonmammalian vertebrates by cells of the ultimobranchial bodies, which are discrete calcitonin-secreting glands. Calcitonin lowers the concentration of calcium in the blood when it rises above the normal value. It has the opposite effect of parathyroid hormone (parathormone).
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