Figure 5

UML diagram of the oligomerization-induced cooperativity effects in HEK-293 cells co-expressing μ-opioid and δ-opioid receptors. The attribute bindingXTalk compiles any information related to changes in the affinity of the ligandUnderTest (DAMGO) in the presence of another ligand (e.g., TIPP Ψ, deltorphin II, SNC80, or DPDPE). Treatment of HEK-293 cells with the selective δ-opioid ligand TIPP Ψ results in increased binding of the μ-opioid agonist DAMGO (see CrossTalk1). Among the δ-opioid selective agonists SNC 80, DPDPE or deltorphin II, only the last leads to a significant increase in DAMGO's binding affinity (see CrossTalk2-4).