Table 1. Pharmacological parameters. Potency (pEC₅₀) and E_max of N/OFQ, N/OFQ(1–13)-NH₂, MCOPPB, and Ro65-6570 are reported (mean of 6 experiments).

Agonist	pEC50 [CL95%]	E max ± SEM
N/OFQ	10.55 (10.25–10.84)	142 ± 12
N/OFQ(1–13)-NH2	10.00 (9.90–10.10)	143 ± 19
MCOPPB	9.73 (9.18–10.28)	156 ± 15
Ro65-6570	9.14 (8.51–9.77)	147 ± 16