Learn → Glossary → biochemistry

Parathyroid Hormone (PTH)

84-amino-acid peptide hormone secreted by parathyroid chief cells in response to low ionized calcium that restores normocalcemia by mobilizing bone calcium, increasing renal calcium reabsorption and phosphate excretion, and stimulating renal CYP27B1.

Also: PTH, Parathormone

PTH secretion is regulated by the calcium-sensing receptor (CaSR) on chief cells. Chronic hypocalcemia or vitamin D deficiency causes secondary hyperparathyroidism, which over time accelerates bone resorption. Primary hyperparathyroidism (usually adenoma) causes hypercalcemia and hypophosphatemia. Calcimimetics that activate CaSR are used to suppress PTH in CKD.

How one textbook covers it

  • Modern Nutrition in Health and Disease, 12th ed. — Ch 7: Calcium

    PTH secretion is regulated by the calcium-sensing receptor (CaSR) on chief cells. Chronic hypocalcemia or vitamin D deficiency causes secondary hyperparathyroidism, which over time accelerates bone resorption. Primary hyperparathyroidism (usually adenoma) causes hypercalcemia and hypophosphatemia. Calcimimetics that activate CaSR are used to suppress PTH in CKD.

Related terms

Calcitriol, Calcium, Calcium-sensing receptor, FGF23