help button home button Endocrine Society Endocrinology
HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS
This Article
Right arrow Full Text (PDF)
Right arrow Alert me when this article is cited
Right arrow Alert me if a correction is posted
Services
Right arrow Email this article to a friend
Right arrow Similar articles in this journal
Right arrow Similar articles in PubMed
Right arrow Alert me to new issues of the journal
Right arrow Download to citation manager
Right arrow Request Copyright Permission
Citing Articles
Right arrow Citing Articles via HighWire
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by Goff, J. P.
Right arrow Articles by Horst, R. L.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Goff, J. P.
Right arrow Articles by Horst, R. L.

Endocrinology, Vol 131, 101-104, Copyright © 1992 by Endocrine Society

ARTICLES

Effect of dietary calcium or phosphorus restriction and 1,25- dihydroxyvitamin D administration on rat intestinal 24-hydroxylase

JP Goff, TA Reinhardt, GW Engstrom and RL Horst
Agricultural Research Service, National Animal Disease Center, Ames, Iowa 50010-0070.

1,25-Dihydroxyvitamin D-24-hydroxylase (24-hydroxylase) modulates the biological effects of 1,25-dihydroxyvitamin D [1,25-(OH)2D] in tissues. The presence of 24-hydroxylase in intestinal mucosa and the mass of the intestine suggest that the intestine is a major site of catabolism of 1,25-(OH)2D. How intestinal levels of 24-hydroxylase are regulated under various dietary conditions, such as calcium (Ca) or phosphorus (P) restriction, is poorly understood. In a series of trials on weanling and mature rats, the effects of dietary Ca or P restriction were compared with the effects of exogenous 1,25-(OH)2D3 administration on intestinal 24-hydroxylase activity. Exogenous administration of 1,25- (OH)2D3, by single bolus injection or constant infusion, increased intestinal 24-hydroxylase activity significantly. Dietary Ca and P restriction both resulted in increased plasma 1,25-(OH)2D3 concentrations several-fold above control rat values (P less than 0.001) and to levels higher than those achieved by constant infusion of 1.3 ng 1,25-(OH)2D3/h. Dietary Ca restriction increased intestinal 24- hydroxylase 6- to 20-fold above that of rats fed a Ca-replete diet (P less than 0.001). Dietary P restriction had no significant effect on intestinal 24-hydroxylase activity. These data suggest that dietary Ca restriction results in increased plasma levels of 1,25-(OH)2D3, which, in turn, leads to up-regulation of intestinal 24-hydroxylase. Conversely, dietary P restriction prevents 1,25-(OH)2D3-mediated up- regulation of 24-hydroxylase.


This article has been cited by other articles:


Home page
 EndocrinologyHome page
D. Larsson, I. Nemere, L. Aksnes, and K. Sundell
Environmental Salinity Regulates Receptor Expression, Cellular Effects, and Circulating Levels of Two Antagonizing Hormones, 1,25-Dihydroxyvitamin D3 and 24,25-Dihydroxyvitamin D3, in Rainbow Trout
Endocrinology, February 1, 2003; 144(2): 559 - 566.
[Abstract] [Full Text] [PDF]


HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS
Endocrinology Endocrine Reviews J. Clin. End. & Metab.
Molecular Endocrinology Recent Prog. Horm. Res. All Endocrine Journals
Copyright © 1992 by The Endocrine Society