Description
The modes of triazole reproductive toxicity have been characterized by an observed increased in serum testosterone and reduced insemination and fertility indices. The key events involved in the disruption in testosterone homeostasis and reduced fertility remain unclear. Gene expression analysis was conducted on liver from Sprague Dawley rats dosed with myclobutanil (300 mg/kg/day) or triadimefon (175 mg/kg/day) for 6, 24 or 336 hours. Pathway-based analysis highlighted key biological processes affected by all three triazoles in the liver including fatty acid catabolism, steroid metabolism, and xenobiotic metabolism. Within the pathways identified in the liver, specific genes involved in phase I-III metabolism and fatty acid metabolism were affected by all three triazoles. These modulated genes are part of a network of lipid and testosterone homeostasis pathways regulated by the constitutive androstane (CAR) and pregnane X (PXR) receptors. Gene expression profiles from this study indicate triazoles activate CAR and PXR; increase fatty acid catabolism and steroid metabolism in the liver; constituting a plausible series of key events contributing to the observed disruption in testosterone homeostasis.