Calcitonin

Category: peptide

Aliases: Salmon calcitonin, Miacalcin, Fortical

Pharmacological Mechanism

32-residue peptide from thyroid C-cells. Activates calcitonin receptors on osteoclasts → inhibits bone resorption and lowers serum Ca²⁺. Salmon calcitonin is 40× more potent than human form and is the standard pharmaceutical. Modest osteoporosis benefit vs bisphosphonates; main clinical niche is acute hypercalcemia of malignancy (fast onset, short duration).

Half-Life (t½)

SC: 1.5h

Dosing Guidelines

• SC: Typical 200 IU (Range: 200–200 IU)
• IM: Typical 200 IU (Range: 200–200 IU)
• IN: Typical 200 IU (Range: 200–200 IU)

Target Organ Systems

• endocrine
• musculoskeletal

Pathways It Modulates

• Bone remodeling (inhibitor) — osteoclast calcitonin receptor
• cAMP / PKA second-messenger signaling (activator) — calcitonin receptor (Gs)

Chemical Identifiers

• PubChem CID: 118984394
• Formula: C151H226N40O45S3
• Molecular weight: 3417.9 g/mol
• InChIKey: LDVRMNJZLWXJPL-GXQFRRLTSA-N
• SMILES: CC[C@H](C)[C@@H](C(=O)NCC(=O)N[C@@H](C(C)C)C(=O)NCC(=O)N[C@@H](C)C(=O)N1CCC[C@H]1C(=O)N)NC(=O)[C@H](C)NC(=O)[C@H]([C@@H](C)O)NC(=O)[C@H](CCC(=O)N)NC(=O)[C@@H]2CCCN2C(=O)[C@H](CC3=CC=CC=C3)NC(=O)[C@H]([C@@H](C)O)NC(=O)[C@H](CC4=CNC=N4)NC(=O)[C@H](CC5=CC=CC=C5)NC(=O)[C@H](CCCCN)NC(=O)[C@H](CC(=O)N)NC(=O)[C@H](CC6=CC=CC=C6)NC(=O)[C@H](CC(=O)O)NC(=O)[C@H](CCC(=O)N)NC(=O)[C@H]([C@@H](C)O)NC(=O)[C@H](CC7=CC=C(C=C7)O)NC(=O)[C@H]([C@@H](C)O)NC(=O)CNC(=O)[C@H](CC(C)C)NC(=O)[C@H](CCSC)NC(=O)[C@@H]8CSSC[C@@H](C(=O)NCC(=O)N[C@H](C(=O)N[C@H](C(=O)N[C@H](C(=O)NC(C(=O)N8)[C@@H](C)O)CO)CC(C)C)CC(=O)N)N

References

• PMID 64046