Effect of high-fructose and high-fat diets on pulmonary sensitivity, motor activity, and body composition of brown Norway rats exposed to ozone

Abstract

Diet-induced obesity has been suggested to lead to increased susceptibility to air pollutants such as ozone (O₃); however, there is little experimental evidence. Thirty day old male and female Brown Norway rats were fed a normal, high-fructose or high-fat diet for 12 weeks and then exposed to O₃ (acute – air or 0.8 ppm O₃ for 5 h, or subacute – air or 0.8 ppm O₃ for 5 h/d 1 d/week for 4 weeks). Body composition was measured non-invasively using NMR. Ventilatory parameters and exploratory behavior were measured after the third week of subacute exposure. Bronchoalveolar lavage fluid (BALF) and blood chemistry data were collected 18 h after acute O₃ and 18 h after the fourth week of subacute O₃. The diets led to increased body fat in male but not female rats. O₃-induced changes in ventilatory function were either unaffected or improved with the fructose and fat diets. O₃-induced reduction in exploratory behavior was attenuated with fructose and fat diets in males and partially in females. O₃ led to a significant decrease in body fat of males fed control diet but not the fructose or fat diet. O₃ led to significant increases in BALF eosinophils, increase in albumin, and reductions in macrophages. Female rats appeared to be more affected than males to O₃ regardless of diet. Overall, treatment with high-fructose and high-fat diets attenuated some O₃ induced effects on pulmonary function, behavior, and metabolism. Exacerbation of toxicity was observed less frequently.

• Air pollution
• BALF biomarkers
• food consumption
• metabolism
• obesity
• penH

Acknowledgements

We thank Drs. Joyce Royland and Desinia Johnson for their review of the manuscript. We also thank Dr. K. Jarema for providing additional statistical support.

Declaration of interest

The research described in this article has been reviewed by the National Health and Environmental Effects Research Laboratory, U.S. Environmental Protection Agency, and approved for publication. Approval does not signify that the contents necessarily reflect the views and policies of the Agency, nor does the mention of trade names of commercial products constitute endorsement or recommendation for use.

Supplementary material available online