Effect of Chronic Fenvalerate Intoxication on Tissue Concentration of Copper in Goats and Further Exploration of Its Mechanism

This experiment was designed to assess the effect of chronic fenvalerate toxicity on tissue Cu concentration in goats and to explore the pathways responsible for it. A significant decrease in tissue Cu concentration of kidney, heart, and brain while an increase in the liver were recorded in fenvalerate intoxicated goats at 15 mg/kg b.w. orally daily for 270 days. Concentration of total Cu, protein-free Cu, and protein-bound Cu in the wet intestine of fenvalerate-treated goats revealed a significant decrease in Cu concentration of the intestine due to the decrease in trichloroacetic acid (TCA)-insoluble Cu, while TCA-soluble Cu remained almost unaffected. Rabbit duodenal loop technique was used to assess the relative absorption of nonisotopic copper in a living animal. This technique enabled to compare Cu absorption from the lumen of three closely associated loops, each receiving 100 µg of copper along with different doses (0, 15, and 30 µg) of fenvalerate. A significant dose-dependent decrease in Cu absorption from the lumen due to fenvalerate treatment was recorded. A decrease in total copper (TCA-insoluble fraction) suggested an interference in active transport of copper due to the inhibition of absorption of protein-bound copper. It was concluded that fenvalerate interfered in copper absorption mostly by inhibiting its active or mediated transport.