Parathyroid hormone inhibits 25-hydroxyvitamin D3-24-hydroxylase mRNA expression stimulated by 1 alpha,25-dihydroxyvitamin D3 in rat kidney but not in intestine
Using a cDNA probe for rat renal 24-hydroxylase, expression of its mRNA was compared in the rat kidney and intestine. Vitamin D-deficient rats received a single injection of 1 alpha,25-dihydroxyvitamin D3. Expression of 24-hydroxylase mRNA was first detected in the kidney at 3-h post-injection and i...
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Published in | The Journal of biological chemistry Vol. 267; no. 19; pp. 13757 - 13762 |
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Main Authors | , , , , , , , |
Format | Journal Article |
Language | English |
Published |
Bethesda, MD
American Society for Biochemistry and Molecular Biology
05.07.1992
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Subjects | |
Online Access | Get full text |
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Summary: | Using a cDNA probe for rat renal 24-hydroxylase, expression of its mRNA was compared in the rat kidney and intestine. Vitamin
D-deficient rats received a single injection of 1 alpha,25-dihydroxyvitamin D3. Expression of 24-hydroxylase mRNA was first
detected in the kidney at 3-h post-injection and increased thereafter. Similarly, 24-hydroxylase mRNA was expressed in the
intestine after 1 alpha,25-dihydroxyvitamin D3 injection. However, the dose level of 1 alpha,25-dihydroxyvitamin D3 required
to induce the intestinal 24-hydroxylase mRNA expression was only 1/100 the amount required to induce renal 24-hydroxylase
mRNA. Induction of intestinal 24-hydroxylase mRNA expression by 1 alpha,25-dihydroxyvitamin D3 was far more rapid than that
of renal 24-hydroxylase mRNA. Thyroparathyroidectomy shortened the time required to induce expression of renal, but not intestinal,
24-hydroxylase mRNA. Administration of either parathyroid hormone or cAMP to vitamin D-deficient rats greatly reduced the
expression of 24-hydroxylase mRNA in the kidney but not in the intestine. When rats were fed a vitamin D-repleted diet containing
0.7% (adequate) or 0.03% (low) calcium for 2 weeks, intestinal expression of 24-hydroxylase mRNA could be induced only in
the low calcium group. In contrast, renal mRNA expression was preferentially stimulated in the adequate calcium group. These
results clearly demonstrate that the expression of 24-hydroxylase mRNA is down-regulated by parathyroid hormone in the kidney
but not in the intestine. |
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ISSN: | 0021-9258 1083-351X |
DOI: | 10.1016/S0021-9258(18)42278-8 |