Neurochemical changes by inhalation of environmental pollutants sulfur dioxide and hydrogen sulfide: degradation of total lipids, elevation of lipid peroxidation and enzyme activity in discrete regions of the guinea pig brain and spinal cord.

Abstract

This study was undertaken to predict the neurochemical effects of two environmental factors simultaneously. Guinea pigs were exposed alternately to SO2 (10 ppm) and H2S (20 ppm) one hour daily for 30 days. Combined toxicity of SO2 and H2S revealed statistically significant decrement of the total lipids in all the regions of the brain and spinal cord. A significant decrement was also discernible in the levels of phospholipids in the cerebral cortex and spinal cord.While, phospholipids concentration was significantly elevated in cerebellum and in the brain stem. The contents of cholesterol exhibited remarkable depletion in all the regions of the brain and spinal cord. In spite of varied responses of cholesterol and phospholipids, C/P ratio showed decrement in various regions of the brain and spinal cord. The concentration of free fatty acids exhibited increment in cerebral cortex and basal ganglia, but the cerebellum, brain stem and spinal cord showed decrement. Remarkable diminution in the concentration of esterified fatty acids was discernible in cerebral cortex, cerebellum and in the spinal cord. Interestingly, these levels showed significant elevation in the brain stem. On the other hand, the concentration of gangliosides showed a significant increase in basal ganglia, cerebellum and in the brain stem. However, these levels were significantly decreased in the cerebral cortex. Lipid peroxidation and lipase activity showed remarkable elevation in different regions of the brain and spinal cord. The results clearly show that peroxidation of endogeneous lipids has been enhanced by SO2 and H2S and thus led to degradation of brain lipids. However, lipid fractions have exhibited regional heterogeniety.