Strictly speaking, a graph where the x-axis shows the concentration of a drug in the organ bath should not be called a dose-response curve. This is because the graph does not show dose, it shows concentration.
What's the difference between dose and concentration?
For this reason, some people refer to dose-response curves as
concentration-effect curves:
a more accurate description of the graph.
Dose-Response Curve =
Concentration-Effect Curve