Cranial neurotransmitter alteration in newborn piglets exposed to oxygen.

Background: To evaluate the influence of hyperoxia on neurotransmitters in the developing brain of newborn piglets.

Methods: Ten newborn piglets were randomly assigned to hyperoxia (inhaled 100% oxygen) or control (inhaled room air) groups and ventilated for 4 hours. Blood samples were obtained at 0, 15, 30, and then every 30 minutes for 4 hours. Extracts of whole brain tissue were assayed for dopamine, serotonin, and their metabolites using high-performance liquid chromatography.

Results: In comparison with the control group, there was a general trend of lower neurotransmitter content in the brains of the hyperoxia group. In addition, the levels of dopamine and 3,4-dihydroxyphenylacetic acid in the left frontal lobe, and serotonin in the right occipital lobe and left frontal lobe, of the hyperoxia group were significantly lower compared with the control group (p < 0.05).

Conclusion: The results indicate that hyperoxia may alter the production or metabolism of dopamine and serotonin in some cortical areas of the neonatal central nervous system, and it tended to have some inhibitory effects. Therefore, pediatricians should be very judicious in using high oxygen on the developing brain.