Effect of nutritional status and ozone exposure on rat brain serotonin

Ozone is an environmental pollutant that has widely documented deleterious effects on exposed organisms. In Mexico City, this pollutant frequently reaches concentrations that surpass safe health limits. In addition, it has been reported that the prevalence of malnutrition remains high in our childhood population. This experiment was carried out to determine whether malnutrition is a factor contributing to an increase in the risk of damage associated with ozone exposure.

Using an experimental animal model, 21-day-old rats fed normally or with induced malnutrition were subchronically exposed to 0.5 ppm of ozone or fresh air, respectively, for 30 days. At the end of this period and using HPLC, serotonin concentrations were measured in four areas of the brain: cortex, hemispheres, cerebellum, and medulla oblongata.

Malnourished animals had a significant weight deficit beginning at 28 days with respect to well-fed animals. Among the well-fed animals, this phenomenon is seen at 35 days in exposed and non-exposed animals. In the four regions of the brain, malnourished animals show low serotonin concentrations with respect to well-nourished animals. In the cerebellum, there was an interaction between the nutritional factor and ozone exposure, while in the medulla oblongata both factors acted independently.

Our results suggest a multiplicative effect from the nutritional factor and ozone exposure in the changes observed concerning serotonergic metabolism.