Abstract: AIM: To investigate alterations of nNOS mRNA in discrete brain regions of rabbits under propofol anesthesia.METHODS: Thirty rabbits were randomly allocated to three groups with ten each: control group, light anesthetic group, deep anesthetic group. Experimentation groups achieved needing drugged state by using target-controlled infusion of propofol, after one hour the rabbits were executed. Control group ear intravenous injection air caused aeroembolism death.Three groups rabbits were isolated to obtain brains under 0-4 ℃, the levels of nNOS mRNA in cerebellar cortex, parietal cortex were observed under different anesthetic depths.RESULTS: Comparing with control group, the levels of nNOS mRNA both in light anesthetic group and in deep anesthetic group decreased significantly in cerebellar cortex and parietal cortex (P<0.05) of rabbit brain.With the increasing of anesthetic depth, significant decreases in nNOS mRNA levels were observed in cerebellar cortex (P<0.05), but no significant difference was found in parietal cortex(P>0.05).CONCLUSION: Propofol probably exerts its anesthetic action through depressing the activity of nNOS, decreasing the levels of NO and cGMP.The depression differs in different brain regions.

Key words: propofol, target-controlled infusion, anesthetic depth, neuronal nitric oxide synthase, brain