THE EFFECTS OF INTRAPERITONEAL INJECTION OF LIGNOCAINE ON PLASMA CATECHOLAMINE LEVELS IN UNSTRESSED AND STRESSED RATS

Groups of rats were injected intraperitoneally with either saline or lignocaine solutions. Following decapitation 10 or 30 min later, blood was collected and analyzed for plasma adrenaline and noradrenaline content. Controlled stress by means of amplified audio-signals was applied to some groups for 5 min before sampling. Results showed that a rise in adrenaline level was produced by stress as well as by both saline and lignocaine injection 10 min before decapitation. This response had disappeared 30 min after injection. Application of stress following injections of either saline or lignocaine produced greatly raised adrenaline levels after 10 min. After 30 min the increases were much less. It is concluded that lignocaine is unlikely to influence plasma catecholamine levels.