Calcitonin is a peptide hormone that lowers blood calcium level and inhibits bone resorption.
1,2 It belongs to the calcitonin family of peptides, which also includes amylin , calcitonin gene-related peptide , and adrenomedullin.
3 The binding of salmon calcitonin to the human calcitonin receptor (CTR) is not modulated by receptor activity-modifying proteins (RAMPs), which influence affinity of human calcitonin to CTR.
4,5 Salmon calcitonin binds to human CTR2 with IC
50 values of 0.933, 0.224, 0.134, and 0.317 nM alone and with RAMP1, 2, or 3, respectively. It induces cAMP accumulation in COS-7 cells transfected with CTR2 (EC
50 = 0.166 nM).
6 Salmon calcitonin inhibits bone resorption by osteoclasts in a pit formation assay using rat bone slices (ID
50 = 0.003 pg/mL) and lowers calcium level
in vivo in a bioassay of hypocalcemia in rats (ED
15 = 33.9 mg/kg).
7 Formulations containing salmon calcitonin have been used to treat hypercalcemia, bone destruction by osteoporosis, and Paget's disease.
2
1. Foster, G.V. Calcitonin. A review of experimental and clinical investigations Postgrad. Med. J. 44(511),411-422(1968).
2. Chesnut, C.H., III, Azria, M., Silverman, S., et al. Salmon calcitonin: A review of current and future therapeutic indications Osteoporos. Int. 19(4),479-491(2008).
3. Wimalawansa, S.J. Amylin, calcitonin gene-related peptide, calcitonin, and adrenomedullin: A peptide superfamily Crit. Rev. Neurobiol. 11(2-3),167-239(1997).
4. Muff, R., Bühlmann, N., Fischer, J.A., et al. An amylin receptor is revealed following co-transfection of a calcitonin receptor with receptor activity modifying proteins-1 or -3 Endocrinology 140(6),2924-2927(1999).
5. Christopoulos, G., Perry, K.J., Morfis, M., et al. Multiple amylin receptors arise from receptor activity-modifying protein interaction with the calcitonin receptor gene product Mol. Pharmacol. 56(1),235-242(1999).
6. Udawela, M., Christopoulos, G., Tilakaratne, N., et al. Distinct receptor activity-modifying protein domains differentially modulate interaction with calcitonin receptors Mol. Pharmacol. 69(6),1984-1989(2006).
7. McSheehy, P.M., Farina, C., Airaghi, R., et al. Pharmacologic evaluation of the calcitonin analogue SB 205614 in models of osteoclastic bone resorption in vitro and in vivo: Comparison with salmon calcitonin and elcatonin Bone 16(4),435-444(1995).
