Fig. 2.
Binding properties of commonly used OTAs at mOTR, mV1aR, and mV1bR. Competition binding experiments were performed using increasing concentrations (from 10−11 to 10−5 M) of the Gq antagonists atosiban (A), OTA1 (B), OTA2 (C), and OTA3 (D). Ligand binding was determined on membrane preparations of COS7 cells transiently transfected with mOTR (black circles), mV1aR (blue triangles), and mV1bR (red squares). Specific binding was determined in the presence of 2–4 × 10−9 M [3H]OT for mOTR and [3H]AVP for mV1aR and mV1bR; nonspecific binding was determined in the presence of OT or AVP (10−3 M). Each curve is the mean of triplicate determinations of a single representative experiment.