Representative plots of in vitro autoradiography saturation binding studies of human, non-human primates (baboon, cynomolgus, rhesus) and rodent (mouse, rat) submandibular glands; each point (n = 6 points) is derived from ROI analysis. For each plot: Bt = Bound total; Bnsp = Bound non-specific; Bsp = Bound specific (Bt-Bnsp = Bsp). ROI, regions of interest.