Figure. Concentration-dependent activation of ADRA2A by nor­adrenal­ine. Reporter cells were transfected with either the expression plasmid for adreno­ceptor alpha 2A (ADRA2A) or the mock plasmid and treated with various concentrations of nor­adrenal­ine. 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 71 nM.