The effects of commercial local anaesthetic solutions on the isolated rabbit ear artery.

The response of an isolated artery preparation to commercial local anaesthetic solutions containing either prilocaine or lignocaine in the presence of adrenaline or noradrenaline has been examined. In low doses, both local anaesthetics were found to augment the constrictor response to adrenaline, wheras at higher doses the effect of adrenaline was significantly depressed by them. In contrast, noradrenaline's vasoconstrictor response was not potentiated by low doses of lignocaine, although higher dose levels caused a significant reduction in its vasoconstrictor effect.