Table 2. Potencies of nondepolarizing muscle relaxants at adult and fetal forms of the muscle nicotinic acetylcholine receptors (ɛ-AChR and γ-AChR) expressed in HEK293 cells.
| Antagonist | IC50 (nmol/L) | P value | |
|---|---|---|---|
| ɛ-nAChR | γ-nAChR | ||
| Vecuronium | 10.2 (8.7–11.9) | 9.9 (4.6–21.0) | >0.05 |
| Atracurium | 22.3 (14.8–33.7) | 35.9 (23.7–54.5) | <0.01 |
| Rocuronium | 33.5 (25.3–44.3) | 22.3 (17.5–28.5) | <0.05 |
Potencies of nondepolarizing muscle relaxants at nicotinic acetylcholine receptors are expressed as the value achieving 50% of maximal inhibition (IC50) of the inward currents induced by coapplication of 30 μmol/L acetylcholine. For each receptor subtype, drug IC50 values that do not share a superscript were statistically different from each other following one-way analysis of variance and Tukey's multiple comparison method. Potency differences between receptor subtypes were compared for each drug using unpaired two-tailed Student's t-tests (P values).