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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 [5] in the ultimopharyngeal body. [6] It acts to reduce blood calcium (Ca 2+), opposing the effects of parathyroid hormone (PTH). [7]
Calcium metabolism is the movement and regulation of calcium ions (Ca 2+) in (via the gut) and out (via the gut and kidneys) of the body, and between body compartments: the blood plasma, the extracellular and intracellular fluids, and bone. Bone acts as a calcium storage center for deposits and withdrawals as needed by the blood via continual ...
The U.S. Institute of Medicine (IOM) established Recommended Dietary Allowances (RDAs) for calcium in 1997 and updated those values in 2011. [6] See table. The European Food Safety Authority (EFSA) uses the term Population Reference Intake (PRIs) instead of RDAs and sets slightly different numbers: ages 4–10 800 mg, ages 11–17 1150 mg, ages 18–24 1000 mg, and >25 years 950 mg. [10]
Bone resorption is resorption of bone tissue, that is, the process by which osteoclasts break down the tissue in bones [1] and release the minerals, resulting in a transfer of calcium from bone tissue to the blood. [2] The osteoclasts are multi-nucleated cells that contain numerous mitochondria and lysosomes. These are the cells responsible for ...
PTH is secreted primarily by the chief cells of the parathyroid glands. The gene for PTH is located on chromosome 11. It is a polypeptide containing 84 amino acids, which is a prohormone. It has a molecular mass around 9500 Da. [6] Its action is opposed by the hormone calcitonin. There are two types of PTH receptors.
Calcitonin receptor. The calcitonin receptor (CT) is a G protein-coupled receptor that binds the peptide hormone calcitonin and is involved in maintenance of calcium homeostasis, [5] particularly with respect to bone formation and metabolism. [6][7][8]
Calcium signaling. Shows Ca 2+ release from the endoplasmic reticulum through phospholipase C (PLC) pathway. Calcium signaling is the use of calcium ions (Ca 2+) to communicate and drive intracellular processes often as a step in signal transduction. Ca 2+ is important for cellular signalling, for once it enters the cytosol of the cytoplasm it ...
Due to its limited duration of action (it works for 48–96 hours, then efficacy decreases as the calcitonin receptors are downregulated) its use is limited to acute hypercalcemia as a bridge therapy until more long-term treatments can be initiated. [22]