Pancuronium bromide

Pancuronium dibromide is a competitive AChR antagonist (IC50 = 5.5 nM) and acts as a skeletal muscle relaxant. Pancuronium dibromide interrupts neuromuscular transmission by competing with acetylcholine for receptor sites on the motor end-plate. (In Vitro) :The action of Pancuronium on transmembrane sodium conductance is investigated in dorsal root ganglion neurones of chick embryos. Externally perfused Pancuronium (50 μM to 1 mM) reversibly inhibits the current by a fast mechanism of action. Inhibition is concentration-dependent (with a half-effective dose of 170 μM) but not voltage-dependent. Pancuronium may reduce the sodium current by interacting with the sodium channels in both the resting and open states. (In Vivo) :Pancuronium (0.5 mg/kg; intravenous injection) abolishes the bradycardia induced both by injected acetylcholine (ACh) and by vagal nerve stimulation in guinea-pigs (250-300 g, male) . At doses which produce 100% neuromuscular blockade, Pancuronium (0.04 mg/kg) potentiates vagally-induced bronchoconstriction.Potentiation by Pancuronium of the effects of adrenergic nerve stimulation, is found in rat anococcygeus and vas deferens.