1 alpha, 25-Dihydroxyvitamin D3 nuclear receptors in pituitary

See allHide authors and affiliations

Science  12 Sep 1980:
Vol. 209, Issue 4462, pp. 1247-1249
DOI: 10.1126/science.6250221


Specific binding of 1 alpha,25-dihydroxyvitamin D(3) was found in nuclear and cytosol fractions of the bovine pituitary. For nuclear binding. the dissociation constant was 0.1 namomole per liter, and maximum binding was 104 femtomoles per milligram of protein. In competition studies, 25-hydroxyvitamin D(3) was 300 times weaker than 1 alpha,25-dihydroxyvitamin D(3). The existence of high-affinity sites supports a physiologic role for 1 alpha,25-dihydroxyvitamin D(3) in the pituitary.