Regulation by vitamin D metabolites of parathyroid hormone gene transcription in vivo in the rat - PubMed (original) (raw)

Comparative Study

Regulation by vitamin D metabolites of parathyroid hormone gene transcription in vivo in the rat

J Silver et al. J Clin Invest. 1986 Nov.

Abstract

In vitro 1,25-dihydroxycholecalciferol (1,25(OH)2D3) decreased levels of preproparathyroid(preproPTH) hormone mRNA. We have now pursued these studies in vivo in the rat. Rats were administered vitamin D metabolites i.p. and the levels of preproPTH mRNA were determined in excised parathyroid-thyroid glands by blot hybridization. PreproPTH mRNA levels were less than 4% of basal at 48 h after 100 pmol 1,25(OH)2D3, with no increase in serum calcium. Gel blots showed that 1,25(OH)2D3 decreased preproPTH mRNA levels without any change in its size (833 basepair). Microdissected parathyroids after 1,25(OH)2D3 (100 pmol) showed mRNA levels for preproPTH were 40 +/- 8% of controls, but for beta-actin were 100% of controls. The relative potencies of vitamin D metabolites were: 1,25(OH)2D3 greater than 24,25(OH)2D3 greater than 25(OH)D3 greater than vitamin D3. In vitro nuclear transcription showed that 1,25(OH)2D3-treated (100 pmol) rats' PTH transcription was 10% of control, while beta-actin was 100%. These results show that 1,25(OH)2D3 regulates PTH gene transcription. PTH stimulates 1,25(OH)2D3 synthesis, which then inhibits PTH synthesis, thus completing an endocrinological feedback loop.

PubMed Disclaimer

Similar articles

Cited by

References

    1. J Biol Chem. 1973 Sep 10;248(17):5967-75 - PubMed
    1. Endocrinology. 1985 Nov;117(5):2114-9 - PubMed
    1. J Mol Biol. 1977 Jun 15;113(1):237-51 - PubMed
    1. Arch Biochem Biophys. 1977 Sep;183(1):168-75 - PubMed
    1. Biochemistry. 1977 Oct 18;16(21):4743-51 - PubMed

Publication types

MeSH terms

Substances

LinkOut - more resources