Figure 1
From: The potential for selective pharmacological therapies through biased receptor signaling
Effects of isoproterenol and pirbuterol on rat atrial isometric contraction peak height (inotropy; filled circles) and rate of relaxation (lusitropy; open circles). The concentration-response curve for lusitropy is shifted 3-fold to the left of the curve for inotropy indicating a difference in the intrinsic coupling efficiencies of the β-adrenoceptor to these two physiological processes. Data redrawn from [10].