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 anim als receiving propofol anesthesia. The in vivo microdialysis technique was used in Sprague-Dawley rats (n = 6) to measure the major metaboli tes of dopamine and serotonin, i.e. 3,4-dihydroxyphenylacetic acid (DO PAC), 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 microdi alysis sampling in another group of rats (n = 6). During the experimen t, the rat was infused intravenously (IV) with propofol at a rate of 1 0 mg.kg(-1).h(-1) for 60 min and 60 mg.kg(-1).h(-1) for 40 min. We fou nd that IV infusion of propofol at a rate of 60 mg.kg(-1).h(-1) signif icantly increased DOPAC, HVA, and 5-HIAA. We also determined that thes e changes correlated well with propofol levels in the brain and blood. We concluded that anesthetic doses of propofol increased the function al activities of dopamine and serotonin in the cortex. These increases correlate well with propofol levels in the cortex and blood.