2,3,7,8-Tetrachlorodibenzo-p-Dioxin Causes an Increase in Protein Kinases Growth Hepatic Associated with Epidermal Factor Receptor in the Plasma Membrane

The study found that 2,3,7,8-Tetrachlorodibenzo-p-dioxin (TCDD) caused down-regulation of the epidermal growth factor (EGF) receptor in the liver plasma membrane of male rats, starting two days after a single dose and continuing for 20 days. This down-regulation was linked to increased protein kinase activity, particularly protein tyrosine kinase. Despite no changes in EGF levels or related substances in serum, TCDD led to early eye opening, tooth eruption, and poor body weight gain and hair growth in mouse neonates, indicating toxicological effects. The impact of TCDD on EGF receptors varied between susceptible and tolerant mouse strains, suggesting mediation through the cytosolic/nuclear TCDD receptor regulated by the Ah locus.