Low levels of cadmium chloride alter the immunoprecipitation of corneal cadherin-complex proteins.

The effect of cadmium chloride on the immunoprecipitation of cadherin and the associated adherens junctional proteins, alpha- and beta-catenin, was examined in isolated bullfrog (Rana catesbeiana) corneas utilizing Western blot and enhanced chemoluminescent techniques. Application of either 1.0 microM or 75.0 microM CdCl2 to the corneal endothelium for 2 h markedly decreased the immunoprecipitation of cadherins as compared to paired control corneas. Immunoprecipitation of alpha-catenin was increased in response to both doses of CdCl2, while the immunoprecipitation of beta-catenin was little changed by either cadmium dose. There is accumulating evidence that cadmium may increase epithelial paracellular permeability by interfering with cadherin complex activity at intercellular junctions. The present study suggests that inorganic cadmium in low micromolar concentrations may decrease the integrity of the corneal endothelium, at least in part through a similar mechanism involving disruption of junctional cadherin complex function.