Rapid actions of 1α,25‐dihydroxyvitamin D3 on Ca2+ and phospholipids in isolated rat liver nuclei

FEBS Letters

Honeymano, Thomas W.²  Ray, Rahul³  Baran, Daniel T.¹  Holick, Michael F.³  Sorensen, Ann M.¹ 

[1] Departments of Orthopedics, University of Massachusetts Medical Center, Worcester, MA 01655 USA;Physiology, University of Massachusetts Medical Center, Worcester, MA 01655 USA;Endocrine Unit, Boston City Hospital, Boston MA, USA

关键词: 1α;    25-(OH)2D3;    Ca2+;    nuclear;    Phosphatidylinositol;    nuclear;   

DOI  :  10.1016/0014-5793(89)81529-7

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

The effects of 1α,25-dihydroxyvitamin D₃ (1α,25-(OH)₂D₃) on Ca²⁺ levels and phospholipid metabolism were studied in isolated nuclei prepared from rat liver. Nuclear Ca²⁺ concentration was estimated with the fluorescent indicator Fura 2. In agreement with previous reports, ATP (1 mM) produced a rapid increase in nuclear Ca²⁺ from 188 ±25 to 593 ±121 nM. Exposure to 1α,25-(OH)₂D₃ (20 nM) also produced a rapid increase in nuclear Ca²⁺ to 402±71 nM. The 1β epimer of lα,25-(OH)₂D₃ had no effect. Nuclear phosphatidylinositol was labeled by incubation with [γ-³²p]ATP for 3 h. 1α,25-(OH)₂D₃ produced a two-fold increase in [³²P]lysophosphatidylinositol (LPI) within 5 min from 44 ± 11 to 87 ± 19 cpm/2.5 × 10⁷ nuclei. 1β,25-(OH)₂D₃ had no effect on [su32P]LPI production. Exposure of nuclei to exogenous LPI (15μM) produced an instantaneous increase in nuclear Ca²⁺ to 372±81 nM, comparable to ATP and lα,25-(OH)₂D₃. The rapid effects of 1α,25-(OH)₂D₃ on phospholipid metabolism and Ca²⁺ in isolated nuclei suggest that the steroid may exert effects distinct from the well-characterized receptor-mediated changes in gene expression.

【 授权许可】

Unknown