Fig. 4. Inhibition of carbachol-induced inositol phosphate (IP) accumulation by propofol. IP accumulation was measured in the abscence (control, circles ) and presence of 100 μM ( triangles ) or 300 μM ( diamonds ) propofol. Concentration–response curves for carbachol-induced inositol phosphate accumulation were obtained. Results were normalized to the basal levels of inositol phosphates and expressed as mean ± SD of five separate experiments determined in triplicate.