kalsítonín
Kalsítonín, also known as calcitonin, is a peptide hormone secreted by the parafollicular cells (C cells) of the thyroid gland. It plays a key role in regulating calcium and phosphorus metabolism in the body. The primary physiological function of kalsítonín is to lower blood calcium and blood phosphorus levels. It achieves this by inhibiting osteoclast activity, thereby reducing bone resorption and promoting bone formation. Additionally, it decreases renal tubular reabsorption of calcium and phosphorus. Clinically, kalsítonín is used to treat conditions such as osteoporosis, hypercalcemia, and certain types of bone pain. Its mechanism involves binding to calcitonin receptors on target cells, triggering intracellular signaling pathways that modulate calcium homeostasis.