Martin Kevin J, Akhtar Irme, González Esther A
Division of Nephrology, Saint Louis University, St Louis, MO 63110, USA.
Semin Nephrol. 2004 Jan;24(1):3-9. doi: 10.1053/j.semnephrol.2003.08.019.
Accurate measurements of parathyroid hormone (PTH) in plasma are necessary for the assessment, monitoring, and therapy of disorders of bone and mineral metabolism including renal osteodystrophy. Assays for PTH have evolved to provide 2-site immunometric assays that are highly specific for the intact 84 amino-acid peptide, PTH (1-84). With the advent of such assays, it has been shown that the prior generation of assays, thought to measure intact PTH, in fact, also detected a PTH peptide that was truncated at the N-terminus and that appeared to be similar to PTH (7-84). There has been renewed interest in such circulating PTH fragments in view of the demonstration that PTH (7-84) (and other PTH peptides) might have biologic effects. These effects include an action to oppose the calcemic effect of PTH in vivo and to inhibit bone resorption and osteoclast generation in vitro. These effects appear to be mediated by actions of a receptor for PTH peptides with specificity for the C-terminal region of PTH and distinct from the PTH receptor known to be responsible for all of the classic actions of PTH. Although the C-PTH receptor has not yet been cloned, the observations have opened a new field of research in parathyroid physiology. Clinical applications of the assay of such PTH fragments in relation to the amount of circulating PTH (1-84) concentrations are being sought actively as the new PTH assay methodology is applied to the clinical arena and as the biology of the C-PTH receptor and C-terminal PTH fragments are investigated.
准确测定血浆中的甲状旁腺激素（PTH）对于评估、监测和治疗包括肾性骨营养不良在内的骨与矿物质代谢紊乱至关重要。PTH检测方法已发展为提供对完整的84个氨基酸肽PTH（1-84）具有高度特异性的双位点免疫测定法。随着此类检测方法的出现，已表明先前一代被认为可测量完整PTH的检测方法，实际上也检测到了一种在N端被截断的PTH肽，且该肽似乎与PTH（7-84）相似。鉴于已证明PTH（7-84）（以及其他PTH肽）可能具有生物学效应，人们对这类循环中的PTH片段重新产生了兴趣。这些效应包括在体内对抗PTH的血钙升高作用以及在体外抑制骨吸收和破骨细胞生成。这些效应似乎是由一种对PTH肽具有特异性的受体介导的，该受体对PTH的C端区域具有特异性，且不同于已知负责PTH所有经典作用的PTH受体。尽管C-PTH受体尚未被克隆，但这些观察结果开启了甲状旁腺生理学研究的新领域。随着新的PTH检测方法应用于临床领域以及对C-PTH受体和C端PTH片段生物学特性的研究，人们正在积极寻求与循环中PTH（1-84）浓度相关的此类PTH片段检测的临床应用。
