Paratiroidni hormon
Paratiroidni hormon (PTH, parathormon, paratirin) luče paratiroidne ćelije paraštitaste žlezde kao polipeptid koji sadrži 84 aminokiseline. On deluje tako što povišava koncentraciju kalcijuma (Ca2+) u krvi, dok kalcitonin (hormon koji proizvode parafolikularne ćelije (C ćelije) štitaste žlezde) snižava koncentracije kalcijuma.
PTH deluje tako što povišava koncentraciju kalcijuma u krivi. On se vezuje za receptor paratiroidnog hormona 1 (koji je prisutan u visokim nivoima u kostima i bubrezima) i za receptor paratiroidnog hormona 2 (koji je visoko izražen u centralnom nervnom sistemu, pankreasu, testisima, i posteljici).[1] PTH poluživot je približno 4 minuta.[2] On ima molekularnu masu od 9,4 kDa.[3]
Struktura
уредиhPTH-(1-34) se kristalizuje kao neznatno povijeni, dugački heliksni dimer. Analiza je pokazala da je heliksna konformacija hPTH-(1-34) verovatno bioaktivna konformacija.[5] The N-terminal fragment 1-34 of parathyroid hormone (PTH) has been crystallized and the structure has been refined to 0.9 Å resolution.
Stimulatori
уреди- Sniženi nivo serumskog [Ca2+].
- Blago povišenje novoa serumskog [Mg2+].
- Povišenje nivoa serumskog fosfata (povećanje koncentracije fosfata uzrokuje formiranje kalcijum fosfata, čime se redukuje stimulacija Ca-senzitivnih receptora (CaSr) koji ne reaguju na kalcijum fosfat, te dolazi do povišenja PTH nivoa)
Inhibitori
уреди- Povišeni novo serumskog [Ca2+].
- Jako sniženje serumskog [Mg2+], koje isto tako proizvodi simptome hipoparatiroidizma (kao što je hipokalcemija).[6]
Reference
уреди- ^ Fiziologija na MCG 5/5ch6/s5ch6_11
- ^ Bieglmayer C, Prager G, Niederle B (2002). „Kinetic analyses of parathyroid hormone clearance as measured by three rapid immunoassays during parathyroidectomy”. Clin. Chem. 48 (10): 1731—8. PMID 12324490. Архивирано из оригинала 07. 06. 2011. г. Приступљено 04. 08. 2012.
- ^ Prahalad AK; Hickey RJ; Huang J; et al. (2006). „Serum proteome profiles identifies parathyroid hormone physiologic response”. Proteomics. 6 (12): 3482—93. PMID 16705755. doi:10.1002/pmic.200500929.
- ^ PDB: 1ETE; Savvides SN, Boone T, Andrew Karplus P (2000). „Flt3 ligand structure and unexpected commonalities of helical bundles and cystine knots”. Nat Struct Biol. 7 (6): 486—491. PMID 10881197. doi:10.1038/75896.; rendered via PyMOL.
- ^ Jin L, Briggs SL, Chandrasekhar S, Chirgadze NY, Clawson DK, Schevitz RW, Smiley DL, Tashjian AH, Zhang F (2000). „Crystal structure of human parathyroid hormone 1-34 at 0.9-A resolution”. J. Biol. Chem. 275 (35): 27238—44. PMID 10837469. doi:10.1074/jbc.M001134200.
- ^ Costanzo, Linda S. (2007). BRS Physiology. Lippincott, Williams, & Wilkins. стр. 260. ISBN 978-0-7817-7311-9.
Literatura
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- Martin TJ (2004). „Does bone resorption inhibition affect the anabolic response to parathyroid hormone?”. Trends Endocrinol. Metab. 15 (2): 49—50. PMID 15080150. doi:10.1016/j.tem.2004.01.002.
- Keutmann HT; Sauer MM; Hendy GN; et al. (1979). „Complete amino acid sequence of human parathyroid hormone”. Biochemistry. 17 (26): 5723—9. PMID 728431. doi:10.1021/bi00619a019.
- Keutmann HT, Niall HD, O'Riordan JL, Potts JT (1975). „A reinvestigation of the amino-terminal sequence of human parathyroid hormone”. Biochemistry. 14 (9): 1842—7. PMID 1125201. doi:10.1021/bi00680a006.
- Parkinson DB, Thakker RV (1993). „A donor splice site mutation in the parathyroid hormone gene is associated with autosomal recessive hypoparathyroidism”. Nat. Genet. 1 (2): 149—52. PMID 1302009. doi:10.1038/ng0592-149.
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- Arnold A; Horst SA; Gardella TJ; et al. (1990). „Mutation of the signal peptide-encoding region of the preproparathyroid hormone gene in familial isolated hypoparathyroidism”. J. Clin. Invest. 86 (4): 1084—7. PMC 296835 . PMID 2212001. doi:10.1172/JCI114811.
- Nussbaum SR, Gaz RD, Arnold A (1990). „Hypercalcemia and ectopic secretion of parathyroid hormone by an ovarian carcinoma with rearrangement of the gene for parathyroid hormone”. N. Engl. J. Med. 323 (19): 1324—8. PMID 2215618. doi:10.1056/NEJM199011083231907.
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- Tregear GW; van Rietschoten J; Greene E; et al. (1975). „Solid-phase synthesis of the biologically active N-terminal 1 - 34 peptide of human parathyroid hormone”. Hoppe-Seyler's Z. Physiol. Chem. 355 (4): 415—21. PMID 4474131.
- Niall HD; Sauer RT; Jacobs JW; et al. (1974). „The Amino-Acid Sequence of the Amino-Terminal 37 Residues of Human Parathyroid Hormone”. Proc. Natl. Acad. Sci. U.S.A. 71 (2): 384—8. PMC 388010 . PMID 4521809. doi:10.1073/pnas.71.2.384.
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- Vasicek TJ; McDevitt BE; Freeman MW; et al. (1983). „Nucleotide sequence of the human parathyroid hormone gene”. Proc. Natl. Acad. Sci. U.S.A. 80 (8): 2127—31. PMC 393770 . PMID 6220408. doi:10.1073/pnas.80.8.2127.
- Mayer H, Breyel E, Bostock C, Schmidtke J (1983). „Assignment of the human parathyroid hormone gene to chromosome 11”. Hum. Genet. 64 (3): 283—5. PMID 6885073. doi:10.1007/BF00279412.
- Hendy GN, Kronenberg HM, Potts JT, Rich A (1982). „Nucleotide sequence of cloned cDNAs encoding human preproparathyroid hormone”. Proc. Natl. Acad. Sci. U.S.A. 78 (12): 7365—9. PMC 349267 . PMID 6950381. doi:10.1073/pnas.78.12.7365.
- Hendy GN; Bennett HP; Gibbs BF; et al. (1995). „Proparathyroid hormone is preferentially cleaved to parathyroid hormone by the prohormone convertase furin. A mass spectrometric study”. J. Biol. Chem. 270 (16): 9517—25. PMID 7721880. doi:10.1074/jbc.270.16.9517.
- Costanzo, Linda S. (2007). BRS Physiology. Lippincott, Williams, & Wilkins. стр. 260. ISBN 978-0-7817-7311-9.