Figure 6.

Antagonism of 5-HT-mediated cAMP formation by Ro 04-6790 in stably transfected HEK-293F/rat 5-HT6 cells in either the absence or copresence of forskolin. HEK-293F cells were stably transfected with rat 5-HT6 receptor as described in Methods. Antagonism of 5-HT-dose-dependent cAMP formation was determined after a 2 h serum-free incubation in the presence of increasing concentrations of Ro 04-6790 in either the absence (a, b) or copresence of 1 μM forskolin (c, d) using FlashPlate technology. Mean 5-HT dose-response curves±s.e.m. are shown from five to ten independent experiments performed in duplicate. Schild plots (b, d) were constructed using mean values±s.e.m. The gradient of the best-fit straight line was determined by linear regression. Slope (95% confidence intervals) was between 0.92–1.19 (b) and 0.49–0.99 (d).