Calcitonin, Salmon

Calcitonin, Salmon is a calcium regulating hormone secreted from mammalian thyroid parafollicular cells and in non-mammalian species from the ultimobranchial gland. Calcitonins are single chain polypeptides containing 32 amino-acid residues, showing hypocalcaemic and hypophosphatemic action, with amino-acid structure differing amongst mammalian species. Salmon calcitonin (salcatonin is the synthetic analogue) shows a markedly different sequence to that of the higher vertebrates as well as more potent activity. Eel calcitonin (Elcatonin) possesses a similar amino acid to that of the salmon form but is more stable than natural calcitonins because of the absence of disulfide bridges.