Figure. Concentration-dependent activation of SUCNR1 by succnic acid. Reporter cells were transfected with either the expression plasmid for suc­ci­nate receptor 1 (SUCNR1) or the mock plasmid and treated with various concentrations of succnic acid. Data points shown are the mean ± SEM of an experiment performed in triplicate, and the curve is a fit to Hill equation with an EC50 of 14 µM.