Calcium Homeostasis

Calcium homeostasis is finely regulated by Parathyroid Hormone (PTH), Calcitonin and Vitamin D.

An increase of blood calcium concentration stimulates the release of Calcitonin, a 32-amino acid peptide from the thyroid parafollicular cells (C-cells). It stimulates cyclic nucleotide accumulation in human kidney cortex and medulla, thereby reducing blood calcium. Calcitonin maybe involved in osteoporosis and in Paget's disease.

Compared to human or rat calcitonin, Salmon Calcitonin is more potent in its biological actions such as inhibition of osteoclasts resorption of bones, renal ion excretion modulation, and others. The reason for its potency has been attributed to the fact that salmon Calcitonin forms an amphipathic helix in its amino acids 9-19 region.

Calcitonin opposes the effects of parathyroid hormone (PTH), which is stimulated upon blood calcium concentration decrease.


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