1,25-dihydroxyvitamin D3 receptors and hormonal responses in cloned human skeletal muscle cells

Endocrinology. 1986 Nov;119(5):2214-20. doi: 10.1210/endo-119-5-2214.


Although skeletal muscle is a major calcium-regulated organ, there remains uncertainty about whether muscle is a target organ for the action of 1,25-dihydroxyvitamin D3 [1,25-(OH)2D3]. In this study we examine pure populations of clonally derived human muscle cells for the presence of 1,25-(OH)2D3 receptors and direct responses to the hormone. All of the clones tested exhibited specific [3H]1,25-(OH)2D3 binding, with values ranging from 5-70 fmol/mg protein. Scatchard analysis of binding data revealed a dissociation constant (approximately 100 pM) comparable to that of classical receptors in other target organs. The 1,25-(OH)2D3 receptors sedimented at 3.3S on hypertonic sucrose gradients. Specificity for [3H]1,25-(OH)2D3 was demonstrated on gradients by substantially better competition by 1,25-(OH)2D3 than 25-hydroxyvitamin D3 for the 3.3S receptor binding peak. The 1,25-(OH)2D3 receptor complex bound to DNA-cellulose and eluted as a single peak at 0.2 M KCl. Myoblasts and myotubes did not show significant differences in either the amount or characteristics of the 1,25-(OH)2D3 receptor. In addition to the presence of receptors, cells were tested for functional responsiveness to 1,25-(OH)2D3. Both cell types exhibited a dose-dependent induction of 25-hydroxyvitamin D3-24-hydroxylase enzyme activity after treatment of monolayers with 1,25-(OH)2D3. Incorporation of both leucine and thymidine into growing myoblasts and fused myotubes was inhibited in a dose-dependent fashion after treatment with 1,25-(OH)2D3. In summary, cloned human skeletal muscle cells contain a binding protein compatible with classical 1,25-(OH)2D3 receptors as well as functional responsiveness to 1,25-(OH)2D3 at physiological concentrations of hormone.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Calcitriol / metabolism
  • Cell Division
  • Cellulose / analogs & derivatives
  • Centrifugation, Density Gradient
  • Clone Cells / metabolism
  • DNA / analogs & derivatives
  • DNA Replication / drug effects
  • Humans
  • Kinetics
  • Leucine / metabolism
  • Muscles / drug effects*
  • Muscles / metabolism
  • Protein Biosynthesis
  • Receptors, Calcitriol
  • Receptors, Steroid / metabolism*
  • Thymidine / metabolism


  • DNA-cellulose
  • Receptors, Calcitriol
  • Receptors, Steroid
  • Cellulose
  • DNA
  • Calcitriol
  • Leucine
  • Thymidine