Inflammatory responses induced by fluoride and arsenic at toxic concentration in rabbit aorta

Epidemiological and experimental studies have demonstrated the atherogenic effects of environmental toxicant arsenic and fluoride. Inflammatory mechanism plays an important role in the pathogenesis of atherosclerosis. The aim of the present study is to determine the effect of chronic exposure to arsenic and fluoride alone or combined on inflammatory response in rabbit aorta. We analyzed the expression of genes involved in leukocyte adhesion [P-selectin (P-sel) and vascular cell adhesion molecule-1(VCAM-1)], recruitment and transendothelial migration of leukocyte [interleukin-8 (IL-8) and monocyte chemotactic protein-1 (MCP-1)] and those involved in pro-inflammatory cytokines [interleukin-6 (IL-6)]. We found that fluoride and arsenic alone or combined increased the expression of VCAM-1, P-sel, MCP-1, IL-8, and IL-6 at the RNA and protein levels. The gene expressions of inflammatory-related molecules were attenuated when co-exposure to the two toxicants compared with just one of them. We also examined the lipid profile of rabbits exposed to fluoride and (or) arsenic. The results showed that fluoride slightly increased the serum lipids but arsenic decreased serum triglyceride. We showed that inflammatory responses but not lipid metabolic disorder may play a crucial role in the mechanism of the cardiovascular toxicity of arsenic and fluoride.