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Calcitonin is a major regulator for the expression of renal 25-hydroxyvitamin D3-1alpha-hydroxylase gene in normocalcemic rats.
Proc Natl Acad Sci U S A. 1999 Jul 06; 96(14):8253-8.PN

Abstract

Regulation of vitamin D metabolism has long been examined by using vitamin D-deficient hypocalcemic animals. We previously reported that, in a rat model of chronic hyperparathyroidism, expression of 25-hydroxyvitamin D3-1alpha-hydroxylase (CYP27B1) mRNA was markedly increased in renal proximal convoluted tubules. It is believed that the major regulator for the expression of renal CYP27B1 is parathyroid hormone (PTH). However, in the normocalcemic state, the mechanism to regulate the renal CYP27B1 gene could be different, since plasma levels of PTH are very low. In the present study, the effect of PTH and calcitonin (CT) on the expression of renal CYP27B1 mRNA was investigated in normocalcemic sham-operated rats and normocalcemic thyroparathyroidectomized (TPTX) rats generated by either PTH or CaCl2 infusion. A single injection of CT dose-dependently decreased the expression of vitamin D receptor mRNA in the kidney of normocalcemic sham-TPTX rats. Concomitantly, CT greatly increased the expression of CYP27B1 mRNA in the kidney of normocalcemic sham-TPTX rats. CT also increased the expression of CYP27B1 mRNA in the kidney of normocalcemic TPTX rats. Conversion of serum [3H]1alpha,25(OH)2D3 from 25-hydroxy[3H]vitamin D3 in vivo was also greatly increased by the injection of CT into sham-TPTX rats and normocalcemic TPTX rats, but not into hypocalcemic TPTX rats. In contrast, administration of PTH did not induce the expression of CYP27B1 mRNA in the kidney of vitamin D-replete sham-TPTX rats and hypocalcemic TPTX rats. PTH increased the expression of renal CYP27B1 mRNA only in vitamin D-deficient hypocalcemic TPTX rats. These results suggest that CT plays an important role in the maintenance of serum 1alpha,25(OH)2D3 under normocalcemic physiological conditions, at least in rats.

Authors+Show Affiliations

Department of Biochemistry, School of Dentistry, Showa University, Hatanodai, Shinagawa-ku, Tokyo 142-8555, USA. shinki@dent.showa-u.ac.jpNo affiliation info availableNo affiliation info availableNo affiliation info available

Pub Type(s)

Journal Article
Research Support, Non-U.S. Gov't

Language

eng

PubMed ID

10393981

Citation

Shinki, T, et al. "Calcitonin Is a Major Regulator for the Expression of Renal 25-hydroxyvitamin D3-1alpha-hydroxylase Gene in Normocalcemic Rats." Proceedings of the National Academy of Sciences of the United States of America, vol. 96, no. 14, 1999, pp. 8253-8.
Shinki T, Ueno Y, DeLuca HF, et al. Calcitonin is a major regulator for the expression of renal 25-hydroxyvitamin D3-1alpha-hydroxylase gene in normocalcemic rats. Proc Natl Acad Sci USA. 1999;96(14):8253-8.
Shinki, T., Ueno, Y., DeLuca, H. F., & Suda, T. (1999). Calcitonin is a major regulator for the expression of renal 25-hydroxyvitamin D3-1alpha-hydroxylase gene in normocalcemic rats. Proceedings of the National Academy of Sciences of the United States of America, 96(14), 8253-8.
Shinki T, et al. Calcitonin Is a Major Regulator for the Expression of Renal 25-hydroxyvitamin D3-1alpha-hydroxylase Gene in Normocalcemic Rats. Proc Natl Acad Sci USA. 1999 Jul 6;96(14):8253-8. PubMed PMID: 10393981.
* Article titles in AMA citation format should be in sentence-case
TY - JOUR T1 - Calcitonin is a major regulator for the expression of renal 25-hydroxyvitamin D3-1alpha-hydroxylase gene in normocalcemic rats. AU - Shinki,T, AU - Ueno,Y, AU - DeLuca,H F, AU - Suda,T, PY - 1999/7/8/pubmed PY - 1999/7/8/medline PY - 1999/7/8/entrez SP - 8253 EP - 8 JF - Proceedings of the National Academy of Sciences of the United States of America JO - Proc. Natl. Acad. Sci. U.S.A. VL - 96 IS - 14 N2 - Regulation of vitamin D metabolism has long been examined by using vitamin D-deficient hypocalcemic animals. We previously reported that, in a rat model of chronic hyperparathyroidism, expression of 25-hydroxyvitamin D3-1alpha-hydroxylase (CYP27B1) mRNA was markedly increased in renal proximal convoluted tubules. It is believed that the major regulator for the expression of renal CYP27B1 is parathyroid hormone (PTH). However, in the normocalcemic state, the mechanism to regulate the renal CYP27B1 gene could be different, since plasma levels of PTH are very low. In the present study, the effect of PTH and calcitonin (CT) on the expression of renal CYP27B1 mRNA was investigated in normocalcemic sham-operated rats and normocalcemic thyroparathyroidectomized (TPTX) rats generated by either PTH or CaCl2 infusion. A single injection of CT dose-dependently decreased the expression of vitamin D receptor mRNA in the kidney of normocalcemic sham-TPTX rats. Concomitantly, CT greatly increased the expression of CYP27B1 mRNA in the kidney of normocalcemic sham-TPTX rats. CT also increased the expression of CYP27B1 mRNA in the kidney of normocalcemic TPTX rats. Conversion of serum [3H]1alpha,25(OH)2D3 from 25-hydroxy[3H]vitamin D3 in vivo was also greatly increased by the injection of CT into sham-TPTX rats and normocalcemic TPTX rats, but not into hypocalcemic TPTX rats. In contrast, administration of PTH did not induce the expression of CYP27B1 mRNA in the kidney of vitamin D-replete sham-TPTX rats and hypocalcemic TPTX rats. PTH increased the expression of renal CYP27B1 mRNA only in vitamin D-deficient hypocalcemic TPTX rats. These results suggest that CT plays an important role in the maintenance of serum 1alpha,25(OH)2D3 under normocalcemic physiological conditions, at least in rats. SN - 0027-8424 UR - https://www.unboundmedicine.com/medline/citation/10393981/Calcitonin_is_a_major_regulator_for_the_expression_of_renal_25_hydroxyvitamin_D3_1alpha_hydroxylase_gene_in_normocalcemic_rats_ L2 - http://www.pnas.org/cgi/pmidlookup?view=long&pmid=10393981 DB - PRIME DP - Unbound Medicine ER -