Figure 5.

The effect of the selective 5-HT₄ receptor antagonist GR 113808 on the relaxation curve to prucalopride and R076186 in the human isolated colonic circular muscle. The curves shown superimposed on the mean experimental data points represent simulations using the Hill-equation and the parameters for midpoint location (with horizontal standard error bars), upper asymptote location (with vertical standard error bars) and the Hill slope, that were obtained from the iterative fitting procedure.