Salmon calcitonin () is the type of

calcitonin Calcitonin is a 32 amino acid peptide hormone secreted by parafollicular cells (also known as C cells) of the thyroid (or endostyle) in humans and other chordates. in the ultimopharyngeal body. It acts to reduce blood calcium (Ca2+), opposing ...

hormone found in

salmon Salmon () is the common name In biology, a common name of a taxon or organism (also known as a vernacular name, English name, colloquial name, country name, popular name, or farmer's name) is a name that is based on the normal language of ...

. Similar to humans, salmon calcitonin is a peptide

hormone A hormone (from the Greek participle , "setting in motion") is a class of signaling molecules in multicellular organisms that are sent to distant organs by complex biological processes to regulate physiology and behavior. Hormones are required ...

produced in the ultimobranchial region by parafollicular cells in response to

hypercalcemia Hypercalcemia, also spelled hypercalcaemia, is a high calcium (Ca2+) level in the blood serum. The normal range is 2.1–2.6 mmol/L (8.8–10.7 mg/dL, 4.3–5.2 mEq/L), with levels greater than 2.6 mmol/L defined as hypercalce ...

and lowers blood calcium and phosphate by promoting renal excretion.

Composition

Salcatonin is composed of 32 amino acids, of which 13 differ from human calcitonin. The structure of human calcitonin and salcatonin is as follows: ''Human calcitonin:'' H-Cys¹-Gly-Asn-Leu-Ser-Thr-Cys⁷-Met-Leu-Gly-Thr-Tyr-Thr-Gln-Asp-Phe-Asn-Lys-Phe-His-Thr-Phe-Pro-Gln-Thr-Ala-lle-Gly-Val-Gly-Ala-Pro-NH₂ ''Salcatonin:'' H-Cys¹-Ser-Asn-Leu-Ser-Thr-Cys⁷-Val-Leu-Gly-Lys-Leu-Ser-Gln-Glu-Leu-His-Lys-Leu-Gln-Thr-Tyr-Pro-Arg-Thr-Asn-Thr-Gly-Ser-Gly-Thr-Pro-NH₂ The cysteine in the first and seventh positions form a disulfide bond.

Therapeutic usage

Synthetic salmon calcitonin may be used therapeutically in humans, as it is twenty times more active than human calcitonin and has a longer half-life. It is used as therapy for Paget's disease, severe

, and in some cases,

gynecomastia Gynecomastia (also spelled gynaecomastia) is the abnormal non-cancerous enlargement of one or both breasts in males due to the growth of breast tissue as a result of a hormone imbalance between estrogens and androgens. Updated by Brent Wisse ...

. It is also used as a therapy against osteoporosis working as an inhibitor of osteoclastic

resorption Resorption is the absorption of cells or tissue into the circulatory system The blood circulatory system is a system of organs that includes the heart, blood vessels, and blood which is circulated throughout the entire body of a human or oth ...

and production of osteoclast precursors), having an effectiveness of 40-50 times that of the human analogue. Studies have shown that treatment of with salcatonin can reduce the rate of new fractures in the lumbar spine and the forearm in postmenopausal women. They may also have analgesic effects, relieving bone pain.

Pharmaceutical salmon calcitonin formulations

Calcitonin, as salmon calcitonin (sCT), is available in the pharmaceutical market as an injectable preparation for intravenous, intramuscular or subcutaneous application. Noninvasive sCT preparation as a nasal spray is commercially produced and received US FDA approval under the proprietary name Miacalcin® in 1975 for the treatment of postmenopausal osteoporosis. The bioavailability of Miacalcin® nasal spray relative to the injectable form is between 3% and 5%. Currently, a number of sCT oral preparations are under clinical trials and at least one of them has reached Phase III of clinical approval.

References

Peptide hormones Fish hormones Hormones of calcium metabolism Hormones of the thyroid gland {{biochem-stub