Vitamin E and C in the prevention of metal nephrotoxicity in developing rats

The protective effect of vitamin E and C on sodium chromate (Cr) and thallium (Tl) induced nephrotoxicity was tested in 10- and 55-day-old rats. The concentrations of Cr and Tl were determined in renal cortex and medulla by atomic absorption spectrometry. Urinary volume and protein excretion as well as blood urea nitrogen (BUN) concentration were determined as parameters of nephrotoxicity. Cr and Tl induced nephrotoxicity was significantly more expressed in adult than in young rats. In Cr and Tl nephrotoxicity the protective effect of vitamin E was evident in both age groups. Vitamin E decreased Tl concentration in renal tissue. Therefore its protective effect is not to be attributed to its known antioxidant effect but to lower Tl concentration in renal tissue. Vitamin C was protective in Cr and Tl induced nephrotoxicity in adult rats without influence on metal concentrations in renal tissue. The dose necessary for protection against toxic Cr action in adult rats was not tolerated by young rats. The combined administration of both vitamins abolished the protective effect against Cr nephrotoxicity of the administration of each vitamin alone in adult rats. When vitamin E and C were administered in Tl treated adult and young rats the protective effect was the same as after the administration of each vitamin alone. Possible mechanisms are discussed.