Endocrinology Book

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Parathyroid Hormone

Aka: Parathyroid Hormone, C-Terminal PTH, N-Terminal PTH, Whole Molecule PTH, Intact PTH, Mid-Region PTH, PTH
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  1. Physiology: Parathyroid Hormone (PTH)
    1. PTH is released by Parathyroid Glands in neck
      1. Parathyroids increase PTH when calcium is low
      2. Parathyroids decrease PTH when calcium is high
    2. Pharmacokinetics
      1. PTH is 84 amino-acid peptide
      2. Circulating half-life: 2-5 minutes
      3. Metabolized by liver and Kidney
    3. Mechanism
      1. PTH stimulates Osteoclasts in bone
        1. Osteoclasts mobilize bone calcium
      2. PTH acts at Kidneys to increase Serum Calcium
        1. Increases calcium reabsorption
        2. Kidney activates 25-hydroxyVitamin D
          1. Converts it to 1,25-dihydroxyVitamin D3
          2. Increases intestinal calcium absorption
  2. Testing
    1. Tests to avoid
      1. C-Terminal PTH
      2. N-Terminal PTH
    2. Recommended Test
      1. Whole Molecule PTH by IRMA (Mid-region or Intact PTH)
        1. Measures C-Terminal and N-Terminal PTH
  3. Interpretation: Normal Serum Calcium
    1. Parathyroid Hormone: 10 to 66 pg/ml
      1. Normal Parathyroid Function
  4. Interpretation: High Serum Calcium
    1. Parathyroid Hormone >66 pg/ml
      1. Primary Hyperparathyroidism
      2. Consider MEN I or MEN II
    2. Parathyroid Hormone 10-66 pg/ml
      1. Familial Hypocalciuric Hypercalcemia
        1. 24 hour Urine Calcium to Creatine clearance <0.01
    3. Parathyroid Hormone <10 pg/ml
      1. Parathyroid Cancer
      2. Granulomatous Disease
      3. Milk-Alkali Syndrome
      4. Adrenal Insufficiency
      5. Hyperthyroidism
      6. Prolonged immobilization
      7. Medication related
        1. Lithium
        2. Theophylline
        3. Tamoxifen
  5. Interpretation: Low Serum Calcium
    1. Parathyroid Hormone >66 pg/ml
      1. Secondary Hyperparathyroidism
        1. Renal Failure
        2. Gastrointestinal malabsorption
        3. Hypomagnesemia
    2. Parathyroid Hormone 10 to 66 pg/ml
      1. Pseudohypoparathyroidism
    3. Parathyroid Hormone <10 pg/ml
      1. Hypoparathyroidism
  6. References
    1. Bakerman (1984) ABCs of Lab Data, ILD, Greenville, NC
    2. Einhorn (2001) CMEA Medicine Lecture, San Diego
    3. Taniegra (2004) Am Fam Physician 69(2):333-40

Parathyroid Hormone (C0030520)

Definition (MSH) A polypeptide hormone (84 amino acid residues) secreted by the PARATHYROID GLANDS which performs the essential role of maintaining intracellular CALCIUM levels in the body. Parathyroid hormone increases intracellular calcium by promoting the release of CALCIUM from BONE, increases the intestinal absorption of calcium, increases the renal tubular reabsorption of calcium, and increases the renal excretion of phosphates.
Definition (CSP) polypeptide hormone secreted by the parathyroid glands which maintains intracellular calcium levels in the body; parathyroid hormone increases intracellular calcium by promoting the release of calcium from bone, increases the intestinal absorption of calcium, increases the renal tubular reabsorption of calcium, and increases the renal excretion of phosphates.
Definition (PDQ) Encoded by human PTH Gene (Parathyroid Hormone Family), secreted (parathyroid cells) 115-aa 13-kDa (precursor) Parathyroid Hormone elevates blood Ca2+ levels by dissolving the salts in bone and preventing renal excretion. PTH defects cause familial isolated hypoparathyroidism. (NCI) Check for "http://www.cancer.gov/Search/ClinicalTrialsLink.aspx?id=489119&idtype=1" active clinical trials or "http://www.cancer.gov/Search/ClinicalTrialsLink.aspx?id=489119&idtype=1&closed=1" closed clinical trials using this agent. ("http://nciterms.nci.nih.gov:80/NCIBrowser/ConceptReport.jsp?dictionary=NCI_Thesaurus&code=C41027" NCI Thesaurus)
Concepts Amino Acid, Peptide, or Protein (T116) , Pharmacologic Substance (T121) , Hormone (T125)
MSH D010281
SnomedCT 27518004, 68136009, 4076007, 373752003
English Hormone, Parathyroid, Parathormone, Parathyrin, Parathyroid Hormone (1-84), PTH (1-84), PARATHYROID HORMONE PREPARATIONS, PARATHYROID HORMONES, Parathormone preparation, NOS, Parathormone, NOS, Parathyroid extract, NOS, Parathyroid hormone preparation, NOS, Parathyroid hormone, NOS, PTH, parathyroid hormone, parathormone, parathyrin, PARATHYROID, parathyroid (medication), parathyroid, A1A PARATHYROID HORMONE PREPARATIONS, B34 PARATHYROID HORMONES, Parathormone (substance), Parathyroid Hormone, Parathyroid Hormone [Chemical/Ingredient], Parathyroid-class Hormone, [HS600] PARATHYROID, Parathyroid Hormone [EPC], Parathyroid hormones, parathyroid hormones, Parathyroid Hormones, Parathyroid hormone, PTH - Parathyroid hormone, Parathyroid hormone preparation, Parathormone preparation, Parathyroid extract, Parathyroid hormone agent (substance), Parathyroid hormone agent, Parathyroid hormone preparation (product), Parathyroid hormone preparation (substance), Parathyroid, Parathyroid hormone (substance), Intact parathyroid hormone (substance)
Spanish hormona paratiroidea intacta, preparado con PTH, preparado con hormona paratiroidea (producto), hormona paratiroidea (producto), preparado con hormona paratiroidea, agente con hormona paratiroidea (sustancia), agente con hormona paratiroidea, extracto paratiroideo, hormona paratiroidea (sustancia), hormona paratiroidea, parathormona (concepto no activo), parathormona, preparado con paratohormona, preparado de PTH, preparado de hormona paratiroidea (producto), preparado de hormona paratiroidea (sustancia), preparado de hormona paratiroidea, preparado de paratohormona, Hormona Paratiroidea
Swedish Bisköldkörtelhormoner
Czech parathormon, parathyroidní hormon
Finnish Lisäkilpirauhashormoni
French Parathyrine, PTH (Parathyroid hormone), PTH (1-84), Hormone parathyroïdienne, Parathormone
German PTH (1-84), Parathyrin, Parathormon, Nebenschilddrüsenhormone
Russian GORMONY PARASHCHITOVIDNOI ZHELEZY, PARAT-GORMON, PARATGORMON, PARASHCHITOVIDNOI ZHELEZY GORMON, OKOLOSHCHITOVIDNOI ZHELEZY GORMONY, PARATIREOIDNYI GORMON, ГОРМОНЫ ПАРАЩИТОВИДНОЙ ЖЕЛЕЗЫ, ОКОЛОЩИТОВИДНОЙ ЖЕЛЕЗЫ ГОРМОНЫ, ПАРАТ-ГОРМОН, ПАРАТГОРМОН, ПАРАТИРЕОИДНЫЙ ГОРМОН, ПАРАЩИТОВИДНОЙ ЖЕЛЕЗЫ ГОРМОН
Japanese 上皮小体ホルモン, パラソルモン, 副甲状腺ホルモン
Italian PTH (1-84), Paratormoni, Ormoni paratiroidei (1-84), Paratirine, Ormoni paratiroidei
Croatian PARATIREOIDNI HORMON
Polish Hormon przytarczyc, Parathormon, Paratyreoidyna, Hormon gruczołów przytarczycznych
Portuguese Hormônio Paratireóideo, Hormônio Paratireoidiano
Sources
Derived from the NIH UMLS (Unified Medical Language System)


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