TABLE 3

Receptor binding of [3H]DAMGO and [3H]diprenorphine binding in mMOR-1 and mMOR-1B4

[3H]Diprenorphine binding was performed in membranes from CHO cells stably transfected with the indicated variant constructs. Ki values were determined from at least three independent determinations of IC50 values (Cheng and Prusoff, 1973). Ki values for [3H]DAMGO are from TABLE 2.

Ligand mMOR-1 mMOR-1B4
[3H]DAMGO [3H]Diprenorphine [3H]Diprenorphine
nM
Morphine 5.3 ± 2.0 94.9 ± 18.3 349 ± 79
M6G 5.2 ± 1.8 609.3 ± 110 >1000
DAMGO 1.8 ± 0.5 50.2 ± 2.5 208 ± 23
DADLE 2.1 ± 0.3 137 ± 13 600 ± 48
Endomorphin 1 2.1 ± 0.8 56.4 ± 7.4 >1000
Etorphine 0.7 ± 0.2 6.7 ± 0.4
Fentanyl 48.5 ± 8.0 137 ± 22
Etonitazene 3.0 ± 0.7 6.6 ± 0.5
β-Endorphin 10.8 ± 2.9 34.6 ± 5.5 873 ± 116
Dynorphin A 10.9 ± 0.5 127 ± 29 >1000
NalBzoH 1.9 ± 0.3 5.4 ± 2.0
[Dmt1]DALDA 2.1 ± 0.4 13.6 ± 5.3
Nalorphine 27.4 ± 6.0 80 ± 31
Buprenorphine 0.4 ± 0.1 0.8 ± 0.2
Naloxone 4.3 ± 0.9 8.2 ± 1.0 17.6 ± 1.8
Diprenorphine 1.0 ± 0.3 2.4 ± 0.2
Naltrexone 1.4 ± 0.1 6.1 ± 0.4
CTAP 1.9 ± 0.2 8.0 ± 1.3
CTOP 3.5 ± 0.3 18.8 ± 4.3
Nor-BNI 188 ± 28 267 ± 34
Naltrindole 66.7 ± 3.3 198 ± 33
U50,488H >500 >1000 >1000
DPDPE >500 >1000 >1000
  • CTOP, d-Phe-Cys-Tyr-d-Trp-Orn-Thr-Pen-Thr-NH2; NalBzoH, naloxone benzoyl-hydrazone.