Table 2. [³H]Diprenorphine displacement with 6′-GNTI and other opioid ligands.

Binding affinity	6′GNTI	Diprenorphine	NorBNI	NTI
IC50, nM
KOP	50.9 ± 9.8	1.09 ± 0.7	0.012 ± 0.02	26.6 ± 4.2
DOP	4.7 ± 1.4	1.9 ± 2.3	81.2 ± 1.4	0.004 ± 0.006
MOP	264.4 ± 66.7	0.5 ± 0.06	192.3 ± 37.8	34.6 ± 8.9
IC50H, nM
KOP/DOP	7.7 ± 1.7	1.13 ± 0.2	0.34 ± 08 (569.8 ± 18.7)*	0.46 ± 0.5 (112.2 ± 3.5)*
KOP/MOP	34.9 ± 10.1	0.97 ± 0.02	12.0 ± 2.8 (>1,000)*	78.9 ± 22.2
DOP/MOP	195.1 ± 48.2	0.99 ± 0.1	931.1 ± 79.5	37.4 ± 2.1

Data are mean ± SEM (n = 2-3). IC₅₀H, high-affinity IC₅₀.

^*Values in parentheses represent the low-affinity IC₅₀ values.