Chronic exposure to low doses of ozone produces a state of oxidative stress and blood-brain barrier damage in the hippocampus of rat

Abstract

Chronic exposure to low doses of ozone similar to a day of high pollution in Mexico City causes a state of oxidative stress. This produces a progressive neurodegeneration in hippocampus of rats exposed to the gas. The aim of this study was to analyze the effect of chronic exposure on the changes in the blood-brain barrier in rats exposed to low doses of ozone. Method: each group received one of the following treatments, control group received air without ozone, and groups 2, 3, 4, 5, and 6 received ozone doses of 0.25 ppm for 4 h daily during 7, 15, 30, 60 and 90 days respectively. Each group was processed to inmunohistochemical technique against of the following antibody: blood-brain barrier, guanylyl cyclase, Iba-1, GFAP, NF κ -B, TNF- α . The results show that there is a correlation between the time exposure of ozone and the progressive damage, on the blood-brain barrier rupture, finally causing edema of endothelial cell, increase in guanylyl cyclase type 1, thickening of the processes and astrocytes foot, and an increase in the expression of factors NF κ -B and TNF- α at 30 and 60 days of exposure to this gas. All the above indicates that the chronic state of oxidative stress causes a neurodegeneration process, accompanied by disruption of the blood-brain barrier likely to occur in the Alzheimer’s disease.