PTHsekretionen
PTHsekretionen refers to the release of parathyroid hormone (PTH) from the parathyroid glands. PTH is a peptide hormone produced by the chief cells of the four parathyroid glands and is a central regulator of calcium and phosphate homeostasis. Secretion is tightly governed by the concentration of ionized calcium in the blood via the calcium-sensing receptor (CaSR) on parathyroid cells: low serum calcium stimulates PTH release, while high calcium suppresses it. Magnesium status and phosphate balance can modulate secretion, and calcitriol (active vitamin D) also exerts feedback influences.
PTHacts on bone, kidney, and, indirectly, the intestine. In bone, PTH promotes osteoblasts to increase RANKL
Clinical relevance includes disorders of PTHsekretionen such as primary hyperparathyroidism (autonomous PTH excess), secondary hyperparathyroidism (a