What Is a Parathyroid Hormone?

Parathyroid hormone (PTH) is a basic single-chain polypeptide hormone secreted by parathyroid main cells. Its main function is to regulate the metabolism of calcium and phosphorus in vertebrates, which promotes the increase of blood calcium levels and the decrease of blood phosphorus levels. PTH promotes the increase of plasma calcium ion concentration, and its main target organs are bone and kidney. It mobilizes bone calcium into the blood, promotes the reabsorption of calcium ions and excretion of phosphate by the renal tubules, increases the blood calcium concentration and decreases the phosphorus concentration. In addition, PTH also indirectly promotes intestinal absorption of calcium ions. The secretion of PTH is mainly regulated by the plasma calcium ion concentration. The increase of plasma calcium ion concentration will inhibit the secretion of PTH; the decrease of plasma calcium ion concentration will stimulate the secretion of PTH. The detection methods of PTH include chemiluminescence immunoassay, radioimmunoassay and enzyme-linked immunoassay.

Basic Information

Chinese name

Parathyroid hormone

English name

parathyroid hormone

nickname

Xenacase

Chemical formula

C22H22F3N

Molecular weight

8771.26

CAS Registry Number

226256-56-0

Short name

PTH

Make up

Consists of 84 amino acids

Clinical significance of parathyroid hormone

PTH measurement can help judge parathyroid function.

1. Elevation: Plasma PTH is significantly higher than normal, and an increase in serum calcium concentration cannot inhibit the secretion of parathyroid hormone, which may be primary hyperparathyroidism; ectopic hyperparathyroidism Disease: hormones may be secreted by ectopic tumors other than parathyroid glands. Such as renal cancer and bronchial cancer PTH increased, but it is not affected by blood calcium concentration; plasma PTH levels are normal or slightly higher, if patients with both low calcium and high blood phosphorus, can be considered as pseudoparathyroid Hypofunction; third stage hyperparathyroidism: after long-term secondary hyperparathyroidism, autonomous hyperparathyroidism may occur.

2. Decrease: idiopathic hypoparathyroidism, hypomagnesemia hypoparathyroidism, hypocalcemia due to reduced PTH secretion; nonhyperthyroid hypercalcemia such as malignant tumors , Sarcoidosis, vitamin D poisoning, hyperthyroidism, and others inhibit PTH secretion due to hypercalcemia.

Reference range of normal parathyroid hormone

<70pg / ml