Figure 4.

CCK regulates CART transcription in luciferase promoter–reporter assays. A, Cultured vagal afferent neurons were transfected with empty vector (empty) and deletional mutants of the CART promoter of 3451, 3100, 620, and 120 bp upstream of the transcriptional start site in luciferase reporter vectors (empty, empty vector). Studies were performed 16 h after transfection when cells were transferred to serum-free medium and stimulated (filled bars) or not (open bars) with 10 nm CCK for 6 h. B, In vagal afferent neurons transfected with 3451CART-Luc, the response to 10 nm CCK was inhibited by 1 μm Ro-32-0432. C, In vagal afferent neurons transfected with 3451 CART-Luc, the effect of 10 nm CCK was inhibited by preincubation for 30 min with 10 nm ghrelin (Gh). Responses to CCK are expressed relative to the appropriate control (1.00). *p < 0.05, **p < 0.01,*** p < 0.001 (t test; n = 6–15). Error bars indicate SEM.