Figure 2.

(a) Concentration-effect relationships for l-menthol–mediated inhibition of the binding of [³H]-WIN35,428 to the human recombinant dopamine transporter and for GBR12909. Tests were duplicated at each concentration, and data are expressed as the mean values of duplicate samples. (b) Linearized concentration-effect relationships for l-menthol–mediated inhibition of the [³H]-WIN35,428 binding and for GBR12909, prepared using logit transformation. Y = logit y = ln (y/1 – y); y = (B–N)/(B₀–N); B = the amount of radioactivity bound in the presence of the test compound, B₀ = the amount of radioactivity bound in the absence of the test compound, N = the amount of radioactivity nonspecifically bound: X = log x; x = the concentration of l-menthol or positive control substance.