Receptor for 1,25-dihydroxyvitamin D in a vascular smooth muscle cell line derived from rat aorta

Abstract

The presence of a specific receptor for 1,25-dihydroxyvitamin D (1,25(OH) 2D) was investigated in a cell line A 7r5 derived from fetal aorta. 1,25(OH) 2[ 3H]D 3 binding to cytosol was saturated at 0.6–1 nM, and Scatchard analysis yielded dissociation constant and binding sites, (3.02 ± 0.4) × 10 −11 M and 33.9 ± 5.8 fmol/mg protein, respectively. Sucrose density gradient analysis revealed the sedimentation constant 3.2S. Furthermore, the receptor protein had affinity for DNA-cellulose column and eluted with 0.2 M KCl. These data suggest that vascular smooth muscle cell may be a target tissue of vitamin D.