Parathyroid hormone (PTH)

Parathyroid hormone (parathyroidhormone) is a basic single-chain peptide hormone secreted by the parathyroid main cells. Referred to as PTH. Parathyroid hormone is composed of 84 amino acids. Its main function is to regulate the metabolism of calcium and phosphorus in vertebrates, promote blood calcium levels and decrease blood phosphorus levels. The first precursor substance of PTH is first synthesized in the main cells of the parathyroid gland, which is called proparathyroid hormone, which contains 115 amino acids. Later, this precursor substance is cleaved intracellularly into a second precursor substance containing 90 amino acids. Parathyroid hormone, which in turn is cleaved intracellularly into a polypeptide of 84 amino acids, PTH. The concentration of PTH in normal human plasma is about 1 ng/ml. The main action of parathyroid hormone increases the activity and number of osteoclasts, increases blood calcium, inhibits the absorption of phosphorus by renal tubules, and promotes the absorption of intestinal calcium and phosphorus. Clinically, radioimmunoassay and immunochemical fluorescence assay are commonly used. Basic Information Specialist classification: growth and development check classification: endocrine examination Applicable gender: whether men and women apply fasting: fasting Tips: Before the inspection, you must stop eating foods rich in iodine, such as kelp, seaweed, sea fish and shrimp, etc., depending on the amount of food, stop eating for 2 to 4 weeks. Normal value The radioimmunoassay has an amino terminus (active end) of 230 to 630 ng/L and a carboxyl terminus (inactive end) of 430 to 1860 ng/L. Immunochemical fluorescence method 1 ~ 10pmol / L. Clinical significance Abnormal result Increase plateau hyperparathyroidism, ectopic hyperparathyroidism, hyperparathyroidism secondary to nephropathy, pseudohypoparathyroidism. Reduce hypoparathyroidism caused by hypothyroidism, renal failure, and hyperthyroidism caused by hyperthyroidism. People who need to be checked Hyperthyroidism, renal failure, joint pain, muscle atrophy. Low results may be diseases: pseudohypoparathyroidism, renal failure precautions Before inspection: 1. Before the inspection, you must stop eating foods rich in iodine, such as kelp, seaweed, sea fish and shrimp, etc., depending on the amount of food, stop eating for 2 to 4 weeks. 2. The following drugs should be stopped before the examination. According to the dosage and time, stop taking 2~8 weeks. (1) Iodine-containing drugs, such as iodide, compound iodine solution, iodine-containing tablets, and the like. (2) Drugs that affect thyroid function, such as thyroid tablets, antithyroid drugs, etc. (3) Some Chinese herbal medicines, such as seaweed, kelp, fritillary, burdock, Mutong, etc. When checking: Check that the patient should be fasting on the day. Not suitable for the crowd: no. Inspection process A common method for determining serum hormones is radioimmunoassay (RIA). This method combines the sensitivity of radiation with the specificity of the immune response and is a reliable, economical and specific assay. It is not affected by the amount of iodine contained in food; it is harmless to the human body after blood collection, and can be applied to pregnant women, lactating women, newborns and endangered patients; this method takes small blood volume and can be measured in other fields. It can also be repeatedly measured and widely used in clinical practice. Not suitable for the crowd Generally no taboos. Adverse reactions and risks Generally not.