The administration of an active vitamin D3 analogue reduced the serum concentrations of 1-84 and truncated parathyroid hormone in pseudohypoparathyroidism type Ib patients

• Ishii Akira

  Department of Metabolism, Endocrinology and Molecular Medicine, Osaka City University Graduate School of Medicine, Osaka, Japan

• Imanishi Yasuo

  Department of Metabolism, Endocrinology and Molecular Medicine, Osaka City University Graduate School of Medicine, Osaka, Japan

• Kurajoh Masafumi

  Department of Metabolism, Endocrinology and Molecular Medicine, Osaka City University Graduate School of Medicine, Osaka, Japan

• Nagata Yuki

  Department of Metabolism, Endocrinology and Molecular Medicine, Osaka City University Graduate School of Medicine, Osaka, Japan

• Kobayashi Keisuke

  Department of Metabolism, Endocrinology and Molecular Medicine, Osaka City University Graduate School of Medicine, Osaka, Japan

• Miki Takami

  Department of Geriatrics and Neurology, Osaka City University Graduate School of Medicine, Osaka, Japan

• Inaba Masaaki

  Department of Metabolism, Endocrinology and Molecular Medicine, Osaka City University Graduate School of Medicine, Osaka, Japan

• Nishizawa Yoshiki

  Department of Metabolism, Endocrinology and Molecular Medicine, Osaka City University Graduate School of Medicine, Osaka, Japan

抄録

Serum calcium is one of major regulators of PTH amino-terminal (N-terminal) truncation and secretion of fulllength (1-84)PTH from parathyroid glands. However, the effect of active vitamin D₃ on PTH truncations remains controversial. To determine whether active vitamin D₃ accelerates the truncation of PTH, the vitamin D₃ analogue alfacalcidol was administered to patients with pseudohypoparathyroidism type Ib (PHP Ib). Both the (1-84)PTH molecule and N-terminally truncated fragments such as (7-84)PTH can be measured by commercially available two-site total PTH (T-PTH) assays. The development of whole PTH (W-PTH) assays specific for full-length (1-84)PTH has enabled us to distinguish between N-terminally truncated PTH and full-length (1-84)PTH. W-PTH/T-PTH ratios were calculated and used as an index of PTH N-terminal truncations. Both serum W-PTH and T-PTH levels were elevated in untreated PHP Ib patients. The administration of alfacalcidol reduced both the W-PTH and T-PTH levels; however, the W-PTH/T-PTH ratios were stable. Serum calcium levels were significantly and negatively correlated with both the W-PTH and T-PTH levels, but not with the W-PTH/T-PTH ratios. Thus, the administration of an active vitamin D₃ analogue did not seem to have a major effect on the rate of PTH N-terminal truncation, even though it did reduce the secretion of both full-length and truncated PTH. Possibly, active vitamin D₃ attenuates the effect of elevated calcium on PTH N-terminal truncation in PHP Ib patients.

収録刊行物

• Endocrine Journal

  Endocrine Journal 57 (7), 609-614, 2010

  一般社団法人 日本内分泌学会

キーワード

• Active vitamin D<SUB>3</SUB>
• Calcium-sensing receptor (CaR)
• N-terminal truncation
• Parathyroid hormone (PTH)
• Whole PTH

詳細情報

• CRID: 1390001206299847680
• NII論文ID: 10029585592
• NII書誌ID: AA10901436
• DOI: 10.1507/endocrj.k10e-012
• ISSN: 13484540
• ISSN: 09188959
• Web Site: http://www.jstage.jst.go.jp/article/endocrj/57/7/57_K10E-012/_pdf
• Web Site: https://search.jamas.or.jp/link/ui/2011064893
• 本文言語コード: en
• データソース種別:
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  • Crossref
  • CiNii Articles
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