Figure 4. Allosteric activity of W-18 on agonist stimulated inhibition of cAMP accumulation at opioid receptors.
The Gi-mediated inhibition of cAMP production was determined as previously described (9–11) and in Methods. W-18 failed to modify the effect of DADLE at DOR (A), dynorphin A at KOR (B), dermorphin at MOR (C), or nociceptin at NOP (D) receptors. Normalized results represent mean ± SEM of 3 independent experiments, each performed in triplicate (0% for vehicle activity and 100% for reference activity), and were analyzed in Prism.