Hana Mušinović1, M Luisa Bonet, Nuria Granados, Jaume Amengual, Johannes von Lintig, Joan Ribot, Andreu Palou. 1. Laboratory of Molecular Biology, Nutrition and Biotechnology, Nutrigenomics-group, Universitat de les Illes Balears, and CIBER de Fisiopatología de la Obesidad y Nutrición (CIBERobn), Palma de Mallorca, Spain; Department of Pharmacology, School of Medicine, Case Western Reserve University, Cleveland, OH, USA.
Abstract
SCOPE: We studied β-carotene (BC) absorption and metabolism and compared BC and retinyl palmitate (RE) for their impact on white adipose tissue (WAT) development in suckling rats. METHODS AND RESULTS: Rat pups received daily orally from days 1-20 of life either the vehicle or vitamin A (approx. ×3 that ingested daily from maternal milk) in the form of BC or RE. Intact BC was found in serum and liver of BC-supplemented rats. Both BC and RE supplementation increased retinoic acid mediated transcriptional responses in intestine (on Isx and Bco1) and the liver (on Cyp26a1 and Cpt1a). In contrast, responses in WAT were dependent on the vitamin A source: WAT of BC-supplemented rats, like WAT of control rats, was enriched in larger adipocytes with increased adipogenic markers (peroxisome proliferator-activated receptor γ and downstream genes) and reduced markers of proliferative status (proliferating cell nuclear antigen) compared to WAT of RE-supplemented rats. CONCLUSION: BC is partly absorbed intact by suckling rats, which resembles the situation in humans and suggests that suckling rats may be an appropriate animal model to study BC uptake, metabolism and biological activity, particularly in infants. Vitamin A supplementation with BC or RE in early life differentially affects WAT and may thus entail different outcomes regarding adiposity programming.
SCOPE: We studied β-carotene (BC) absorption and metabolism and compared BC and retinyl palmitate (RE) for their impact on white adipose tissue (WAT) development in suckling rats. METHODS AND RESULTS:Rat pups received daily orally from days 1-20 of life either the vehicle or vitamin A (approx. ×3 that ingested daily from maternal milk) in the form of BC or RE. Intact BC was found in serum and liver of BC-supplemented rats. Both BC and RE supplementation increased retinoic acid mediated transcriptional responses in intestine (on Isx and Bco1) and the liver (on Cyp26a1 and Cpt1a). In contrast, responses in WAT were dependent on the vitamin A source: WAT of BC-supplemented rats, like WAT of control rats, was enriched in larger adipocytes with increased adipogenic markers (peroxisome proliferator-activated receptor γ and downstream genes) and reduced markers of proliferative status (proliferating cell nuclear antigen) compared to WAT of RE-supplemented rats. CONCLUSION:BC is partly absorbed intact by suckling rats, which resembles the situation in humans and suggests that suckling rats may be an appropriate animal model to study BC uptake, metabolism and biological activity, particularly in infants. Vitamin A supplementation with BC or RE in early life differentially affects WAT and may thus entail different outcomes regarding adiposity programming.