Regulation of SREBP-1 mRNA by RXR and LXR agonists in liver (A), white adipose tissue (B), and small intestine (C). Male wild-type and Lxrα/β−/− mice were fed diets containing 0.2% cholesterol plus vehicle (open bars), 30 mpk LG268 (hatched bars), or 50 mpk T0901317 (black bars) for 12 h. Northern analysis was performed on mRNA individually (A) or as a pooled sample consisting of three to four animals per group (B,C). Relative mRNA levels in liver (A) are expressed as the mean ± SEM, and a representative Northern blot is shown above. Small intestine mRNA was isolated from the mucosa of the duodenum (D), jejunum (J), and ileum (I).