Effect of propofol on dopamine metabolism in the rat prefrontal cortex under noxious stimulation

Abstract

Although there has been increased use of propofol for sedation during dental treatment, there have been few reports on its effect on the central nervous system. I used microdialysis to examine the effect of propofol on dopamine metabolism in the rat prefrontal cortex to study its influence on the central nervous system. Rats were anesthetized and a microdialysis probe was implanted into the left prefrontal cortex. After one week, Ringer's solution was perfused in the probe at a flow rate of 2μL/min, and samples were collected every 20 minutes. Samples were then injected immediately into a high performance liquid chromatography system with an electrochemical detector. The dopamine level of the rats receiving physiological saline was significantly increased with the noxious stimulation compared with the animals that did not receive noxious stimulation. The dopamine level of the rats receiving propofol was significantly increased with noxious stimulation compared with those receiving physiological saline. Administrating both propofol and bicuculine with noxious stimulation did not significantly change the dopamine level. Bicuculline significantly antagonized the effect of dopamine release under noxious stimulation with propofol. These results suggest that the effect of propofol might be related to the GABAA receptor.