Membrane lipid changes in organic solvent tolerant neural cells

Lower blood malondialdehyde is associated with past pesticide exposure: findings in Gulf War illness and healthy controls

BACKGROUND

Malondialdehyde (MDA) is a candidate general marker of oxidative stress (OS). We sought to assess the relation of MDA to Gulf War illness (GWI) and to a variety of exposures.

METHODS

This is an observational study involving subjects from Southern California recruited from October 2011 to May 2014. MDA was assessed in 81 participants (41 GWI-cases, 40 controls). General and Gulf-specific exposures were elicited. MDA case-control comparison was restricted to 40 matched pairs. The potential association between MDA and exposures was assessed using regression analyses. Gulf-specific exposures were incorporated into a case-specific model.

RESULTS

Plasma MDA was significantly lower in GWI-cases than controls. Composite pesticide and fuel-solvent exposures negatively predicted MDA in the total sample, as well as in the analyses that included either GWI-cases or controls only. Self-reported exposure to organophosphate (OP) nerve gas was a strong predictor for lower MDA level in veterans with GWI.

CONCLUSION

Past pesticide exposures predicted lower MDA in both veterans with GWI and in healthy controls.

Depressed prostaglandins and leukotrienes in veterans with Gulf War illness

Background: There is need to understand biological markers and mechanisms in Gulf War illness (GWI). Goal: To examine whether and how eicosanoids - prostaglandins and leukotrienes - are altered in veterans with GWI. Methods: Seventy participants including 37 GWI and 33 healthy controls, shared exposure information, and had plasma eicosanoids assessed - prostaglandin F2 alpha (pgf2α), prostaglandin D2 (pgd2), leukotriene B4 (lb4) among others. Values were compared for GWI versus controls. Eicosanoid intercorrelations were compared in cases vs. controls. For the most significantly altered eicosanoid in GWI, exposure and symptom relations were assessed. Results: Prostaglandins and leukotrienes were depressed in GWI, strongest for pgf2α, then lb4. Eicosanoid intercorrelations differed in GWI vs. controls. Fuel-solvent, pesticide, radioactive chemicals and metal exposures related negatively to pgf2α; as, in GWI, did chemical attack and vaccines. Multivariate predictors included fuels-solvents and radioactive chemicals (negative); tetanus vaccine and herbicides (positive). Fuels-solvents and radioactive chemicals predicted lower pgf2α in cases, controls, and all participants controlled for case status. Lower pgf2α related to GWI "Kansas criteria" domains of pain, respiratory, and (borderline significantly) skin symptoms. Conclusion: Multiple eicosanoids are depressed in GWI, particularly pgf2α and lb4. Prior fuel-solvent exposures, radioactive chemicals, and (in GWI cases) vaccines were linked to lower pgf2α.

Fatty acid composition in liver, serum and brain of rat inhalated with trichloroethylene

Temporal variations in chronic effects of inhalated 300 ppm trichloroethylene (TCE) on the fatty acid composition in rats were investigated to clarify influences of TCE on the fatty acid metabolism of serum, liver and brain, including synaptosome, myelin and mitochondria fractions on weeks 0, 4, 8, 12 after exposure and on week 4 after rehabilitation started following 12 weeks exposure. On week 4, rats exposed to TCE had significantly lighter body weight, lighter epididymal fat pads weight and heavier liver weight compared with controls. In liver and serum, increases in 16:0, 18:0, 18:1n-9, 20:2n-6, 20:3n-6 and 20:4n-6 and decreases in 18:2n-6, 18:3n-6, 18:3n-3, 20:5n-3, 22:5n-3 and 22:6n-3 were also observed. The differences between the exposure and the control groups in the fatty acid composition in liver and serum, except for 18:1n-9 and 18:2n-6, did not enhance from week 4 after TCE exposure. In brain, significant changes of fatty acid composition caused by TCE appeared as decreases in 18:2n-6 and 22:5n-3, and increases in 20:4n-6 and 22:4n-6 during the whole exposure period. Changes of fatty acid composition in brain occurred in the same manner as in serum and liver phospholipids, except that 18:1n-9 was elevated in mitochondria. Changes in brain were slighter and appeared later than those in liver and serum. TCE had a strong effect on the fatty acid composition of mitochondria in neural cells.(ABSTRACT TRUNCATED AT 250 WORDS)

Exposure of rats to high concentrations of 1,1,1-trichloroethane and its effects on brain lipid and fatty acid composition

Exposure of rats to 1,1,1-trichloroethane (TRI) (1200 p.p.m.) for 30 days resulted in changes in the fatty acid pattern of the brain ethanolamine phosphoglyceride. A decrease was observed in stearic acid (18:0) and arachidonic acid (20:4), while the 22-carbon (n-3) fatty acids were increased. These changes in the fatty acid pattern were similar to that observed previously in the rat for another solvent, perchloroethylene, at a lower exposure concentration (320 p.p.m). Both these solvents are little metabolised and it seems that a common mechanism exists whereby these solvents alter the fatty acid pattern of brain phospholipid upon exposure. The relatively low uptake of TRI makes a high exposure level (1200 p.p.m.) necessary to attain a blood concentration high enough for the changes to appear.

Regeneration of the sciatic nerve in mice and rats exposed to trichloroethylene

The effects of trichloroethylene (TCE) on regeneration of the sciatic nerve after a crush lesion was tested in mice and rats. A lesion was made on nerves in unexposed animals and in animals pre-exposed to TCE for 20 days. Experimental animals were then exposed to TCE for an additional 4 days. Exposures were continuous at 150 or 300 ppm. Regeneration was measured by pinching the outgrowing nerve fibers. Regeneration was retarded in the TCE-exposed animals compared to the air-exposed controls. Mice were more sensitive to TCE exposure than rats. Liver weight increased in TCE-exposed mice but there was no correlation between this effect and that on nerve regeneration.