Opposite effects of feeding a vitamin A-deficient diet and retinoic acid treatment on brown adipose tissue uncoupling protein 1 (UCP1), UCP2 and leptin expression

The relationship between interscapular brown adipose tissue (IBAT) thermoge nic potential and Vitamin A status was investigated by studying the effects of feeding a vitamin A-deficient diet and all-trans retinoic acid (tRA) tr eatment on body weight and IBAT parameters in mice. Feeding a vitamin A-def icient diet tended to trigger opposite effects to those of tRA treatment, n amely increased body weight, IBAT weight, adiposity and leptin mRNA express ion, and reduced IBAT thermogenic potential in terms of uncoupling protein 1 (UCP1) mRNA and UCP2 mRNA expression. The results emphasize the importanc e of retinoids as physiological regulators of brown adipose tissue.