Does nitrous oxide produce an effect upon brain neurotransmitters namely dopamine, norepinephrine and serotonin and is it the answer to postoperative nausea and vomiting?

ABSTRACT

The effect of nitrous oxide [N2O] was studied on the changes of brain neurotransmitters [dopamine [DA], serotonin [5HT] and norepinephrine [NE]] in rats. Nitrous oxide was found to have no significant effect on the contents of NE, and 5HT, but decreases that of DA [mid- brain], thalamus-hypothalamus and medulla] after one hour. Decreased levels of DA indicated that, N2O increases dopaminergic neuronal activities in the mesocortical projections [midbrain, thalamus and hypothalamus] as well as the medullary network. The euphoric properties of nitrous oxide may be an indication of activation of mesocortical dopaminergic projection, while the increased incidence of emesis may indicate activation of medullary dopaminergic system. The observed plateau of the dopamine effect within the two hours of exposure could reflect the development of an acute tolerance to nitrous oxide. The effect of N2O on the liver function enzymes was studied as well as to investigate whether it has a hepatotoxic effect. Both enzymes tested, ALAT and ASAT, showed no significant difference from control