持续输注甲状旁腺激素的大鼠中，1α,25-二羟维生素D3对25-羟维生素D代谢无调节作用。

Absence of regulatory effects of 1alpha25-dihydroxyvitamin D3 on 25-hydroxyvitamin D metabolism in rats constantly infused with parathyroid hormone.

作者信息

Horiuchi N, Suda T, Sasaki S, Takahashi H, Shimazawa E, Ogata E

机构信息

Department of Biochemistry, School of Dentistry, Tokyo Medical and Dental University, Yushima, Bunkyo-ku, Tokyo 113, Japan.

出版信息

Biochem Biophys Res Commun. 1976 Dec 20;73(4):869-75. doi: 10.1016/0006-291x(76)90202-3.

DOI:10.1016/0006-291x(76)90202-3

PMID:15625855

Abstract

The regulatory role of 1alpha,25-dihydroxyvitamin D3 [1alpha,25-(OH)2-D3] in metabolism of 25-hydroxyvitamin D was studied in sham-operated (sham) or thyroparathyroidectomized (TPTX) vitamin D-deficient rats into which calcium and parathyroid hormone (PTH) were constantly infused. A single dose of 325 or 650 pmol of 1alpha,25-(OH)2-D3 caused significant inhibition of 1alpha,25-(OH)2-D3 synthesis in D-deficient sham rats. This inhibition by 1alpha,25-(OH)2-D3, however, was not observed in D-deficient TPTX rats into which PTH was constantly infused. These results can be explained by supposing that the major regulatory effect of 1alpha,25-(OH) 2-D3 on 1alpha,25-(OH)2-D3 synthesis is realized mostly, if not all, by suppressing endogenous secretion of PTH.

摘要

在假手术（假手术组）或甲状旁腺切除（TPTX）的维生素D缺乏大鼠中，持续输注钙和甲状旁腺激素（PTH），研究1α,25 - 二羟基维生素D3 [1α,25-(OH)2-D3]在25 - 羟基维生素D代谢中的调节作用。给维生素D缺乏的假手术组大鼠单次注射325或650 pmol的1α,25-(OH)2-D3，可显著抑制1α,25-(OH)2-D3的合成。然而，在持续输注PTH的维生素D缺乏TPTX大鼠中未观察到1α,25-(OH)2-D3的这种抑制作用。这些结果可以通过假设1α,25-(OH)2-D3对1α,25-(OH)2-D3合成的主要调节作用即使不是全部，也是主要通过抑制PTH的内源性分泌来实现的来解释。