1,25-dihydroxyvitamin D3 Up-Regulates the 1,25-dihydroxyvitamin D3 Receptor in vivo
Abstract
The level of mRNA encoding the 1,25-dihydroxyvitamin D3 receptor in the intestine of vitamin D-deficient rats given 1,25-dihydroxyvitamin D3 was determined by Northern blot analysis using a 32P-labeled cDNA probe to the 1,25-dihydroxyvitamin D3 receptor. mRNA levels increased 10-fold above deficiency levels at 6 and 12 hr after an intravenous dose of 1,25-dihydroxyvitamin D3, returning to predosing levels at 24 hr. Total receptor protein level determined by an immunoradiometric assay was increased 2-fold at 12 hr. No change in unoccupied receptor levels determined by ligand-binding assay was observed during this period. These results suggest that 1,25-dihydroxyvitamin D3 increases receptor mRNA and total receptor level to maintain constant levels of unoccupied receptor.
- Publication:
-
Proceedings of the National Academy of Science
- Pub Date:
- December 1989
- DOI:
- 10.1073/pnas.86.24.9770
- Bibcode:
- 1989PNAS...86.9770S