Propofol anesthesia increases dopamine and serotonin activities at the somatosensory cortex in rats: A microdialysis study

We sought to estimate the activities of dopamine and serotonin in animals receiving propofol anesthesia. The in vivo microdialysis technique was used in Sprague-Dawley rats (n = 6) to measure the major metabolites of dopamine and serotonin, i.e. 3,4-dihydroxyphenylacetic acid (DOPAC), homovanillic acid (4-hydroxy-3-methyphenylacetic acid; HVA) and 5-hydroxy indole acetic acid (5-HIAA) in the somatosensory cortex. We also measured the levels of propofol in the brain and blood by microdialysis sampling in another group of rats (n = 6). During the experiment, the rat was infused intravenously (IV) with propofol at a rate of 10 mg · kg^-1 · h^-1 for 60 min and 60 mg · kg^-1 · h^-1 for 40 min. We found that IV infusion of propofol at a rate of 60 mg · kg^-1 · h^-1 significantly increased DOPAC, HVA, and 5-HIAA. We also determined that these changes correlated well with propofol levels in the brain and blood. We concluded that anesthetic doses of propofol increased the functional activities of dopamine and serotonin in the cortex. These increases correlate well with propofol levels in the cortex and blood.