TABLE 1.
Relative antinociceptive potency of xendorphin B1 compared to mu, delta, and kappa opioid agonists after intraspinal administration in amphibians. Xendorphin B1 data from present study, other data from previously published work [22] and are included for comparison.
| Opioid Agent | Class | ED50a | (95% C.I.)b | SLOPE | (95% C.I.) | R.P.c |
|---|---|---|---|---|---|---|
| DAMGO | Mu | 0.13 | (0.08–0.2) | 39.4 | (24.1–54.8) | 17.38 |
| Morphine | Mu | 2.26 | (1.7–3.0) | 48.4 | (37.2–59.5) | 1.00 |
| DPDPE | Delta0 | 3.29 | (2.3–4.7) | 56.2 | (35.3–77.0) | 0.69 |
| U50488 | Kappa | 36.82 | (19.3–70.2) | 36.7 | (16.8–56.5) | 0.06 |
| Xendorphin B1 | ? | 44.47 | (20.7–95.4) | 34.2 | (9.0–59.3) | 0.05 |
a
in nmol/animal.
b
95% confidence interval.
c
relative potency compared to morphine: ED50 morphine/ED50 agent.