Effect of cadmium on gap junctional intercellular communication in primarycultures of rat renal proximal tubular cells

Cadmium mainly accumulates in the kidney and causes renal injury. To clarif y the mechanism of Cd nephrotoxicity, we investigated the effects of this e lement on intercellular communication through gap junction channels in prim ary cultures of rat renal proximal tubular cells. Sixty minutes after expos ure to 100 muM Cd, dye coupling experiments showed that gap junctional inte rcellular communication (GJIC) was significantly inhibited. This inhibition occurred before the appearance of cytotoxicity. Intracellular calcium conc entrations [Ca2+](i), which modulate the function of gap junctions, gradual ly increased after exposure to Cd and reached a maximum after 60 minutes. T hese results suggest that the inhibition of GJIC as a result of Cd exposure is related to an increase in [Ca2+](i). and that GJIC inhibition may be an indicator of nephrotoxicity, (C) 2001 Elsevier Science Inc. All rights res erved.