| Title | Retinoic acid cross-talk with calcitriol activity in Atlantic salmon (Salmo salar). | | Author(s) | Ørnsrud R, Lock EJ, Glover CN, Flik G | | Institution | National Institute of Nutrition and Seafood Research, PO Box 2029 Nordnes, N-5817 Bergen, Norway. robin.ornsrud@nifes.no | | Source | J Endocrinol 2009 Sep; 202(3):473-82. | | MeSH | Alkaline Phosphatase
Animal Feed
Animals
Aquaculture
Biological Markers
Calcitriol
Calcium
Calcium-Binding Proteins
Collagen Type II
Cytochrome P-450 Enzyme System
Dose-Response Relationship, Drug
Extracellular Matrix Proteins
Fish Products
Magnesium
Phosphorus
Plant Oils
Receptor Cross-Talk
Salmo salar
Tretinoin
Vitamin A
| | Abstract | Vitamins A (VA) and D (VD) are metabolised by vertebrates to bioactive retinoic acid (RA) and calcitriol (CTR). RA and CTR involvement in bone metabolism requires fine-tuned regulation of their synthesis and breakdown. In mammals antagonism of VA and VD is observed, but the mechanism of interaction is unknown. We investigated VA-VD interactions in Atlantic salmon (Salmo salar L.) following i.p. injection of RA and/or CTR. VA metabolites, CTR, calcium (Ca), magnesium (Mg) and phosphorus (P) were determined in plasma. Expression of bone matrix Gla protein (mgp), collagen 1 alpha2 chain (col1a2) and alkaline phosphatase (alp) mRNA was quantified to reflect osteogenesis. Branchial epithelial Ca channel (ecac listed as trpv6 in ZFIN Database) mRNA levels and intestinal Ca and P influx were determined to study Ca/P handling targets of RA and CTR. RA-injection (with or without CTR) decreased plasma CTR-levels three- to sixfold. CTR injection did not affect RA metabolites, but lowered CTR in plasma 3 and 5 days after injection. Lowered plasma CTR correlated with decreased mgp and col1a2 expression in all groups and with decreased alp in CTR-injected fish. RA-treated salmon had enhanced alp expression, irrespective of reduced plasma CTR. Expression of ecac and unidirectional intestinal influx of Ca were stimulated following RA-CTR treatment. Plasma Ca, Mg and P were not affected by any treatment. The results suggest cross-talk of RA with the VD endocrine system in Atlantic salmon. Enhanced Ca flux and osteogenesis (alp transcription) in RA-treated fish and inhibition of mgp expression revealed unprecedented disturbance of Ca physiology in hypervitaminosis A. | | Language | eng | | Pub Type(s) | Journal Article
Research Support, Non-U.S. Gov't
| | PubMed ID | 19531580 |
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