Table 2

Selectivity of MOR-1 and MOR-1C in receptor binding assays

LigandKiValueANOVATukey
MOR-1MOR-1CMOR-1DMOR-1EMORp
nM
Morphine5.3  ± 2.02.4  ± 0.61.5  ± 0.22.3  ± 0.4<.051 vs 1D:<.05
M6G5.2  ± 1.84.1  ± 1.24.8  ± 0.85.6  ± 0.7N.S.
DAMGO1.8  ± 0.50.93  ± 0.190.71  ± 0.111.2  ± 0.5N.S.
DADLE2.1  ± 0.33.2  ± 1.91.3  ± 0.42.5  ± 0.7N.S.
DSLET12.5  ± 3.68.1  ± 1.23.6  ± 0.66.7  ± 1.4<.051 vs 1D:<.05
Naloxone4.3  ± 0.92.8  ± 0.80.92  ± 0.082.8  ± 1.4N.S.
Endomorphin 12.1  ± 0.81.4  ± 0.41.8  ± 0.32.4  ± 0.1N.S.
Endomorphin 24.2  ± 1.81.6  ± 0.22.0  ± 0.34.4  ± 0.8N.S.
β-Endorphin10.8  ± 2.95.8  ± 0.51.7  ± 0.45.0  ± 1.2<.00031 vs 1D:<.001
1 vs 1E:<.05
Dynorphin A10.9  ± 0.55.6  ± 0.82.2  ± 0.88.9  ± 1.1<.00011 vs 1C:<.05
1 vs 1D:<.001
1C vs 1E:<.05
1D vs 1E:<.001
U50,488H>1000>1000>1000>1000
DPDPE>1000>1000>1000>1000

[3H]DAMGO binding was performed in stable transfectants containing the indicated cDNAs. ANOVA was performed to determine whether there were differences among the various clones for each competitor, followed by Tukey’s post hoc analysis. Competition studies were performed using at least three concentrations of the indicated competitor. Results are the mean ± S.E. of at least three independent determinations.

    • DADLE, [d-Ala2,d-Leu5]-enkephalin; DSLET, [d-Ser2, Leu5]-enkephalin-Thr; DPDPE, [d-Pen2,d-Pen5]-enkephalin.