Evaluation of some immunoregulatory cytokines in serum of rats exposed to cadmium and ethanol

The aim of the present study was to investigate the effects of cadmium (Cd) (5 and 50 mg Cd/l in drinking water) and ethyl alcohol (ethanol, EtOH) (5 g EtOH/kg b.wt., intragastrically), administered alone or simultaneously, on the concentrations of pro-inflammatory (interleukin-1, IL-1?; interleukin-6, IL-6; tumor necrosis factor-?, TNF? and interferon ?, INF?) and anti-inflammatory (interleukin-4, IL-4) cytokines in the serum of rats. In order to estimate the involvement of Cd- or/and EtOH-induced oxidative stress in damage to cytokines, the concentration of protein carbonyl groups (PC), as a marker of oxidative protein damage, was also determined. Exposure to 5 and 50 mg Cd/l, alone or in combination with EtOH, led to an increase in the serum concentrations of IL-1?, TNF? and INF? with a simultaneous decrease in IL-4 concentration, compared to the control. The concentration of IL-6 was elevated only after administration of 50 mg Cd/l, both alone and in combination with EtOH. The exposure to EtOH alone resulted in increased concentrations of TNF? and INF?, as well as in decreased concentrations of IL-4. In rats co-exposed to Cd and EtOH, the changes observed in the concentrations of the cytokines, except in IL-6, were more advanced, compared to the animals treated with these xenobiotics alone. Exposure to Cd and EtOH, both alone and in combination, caused an increase in the serum PC concentration. The concentration of PC positively correlated with the concentrations of IL-1?, IL- 6, TNF? and INF? and negatively with IL-4 concentration. The results suggest that changes in the cytokines examined are more enhanced after combined exposure to Cd and EtOH, especially at higher Cd dosage. Moreover, it can be hypothesized that oxidative stress may be involved in the mechanism leading to changes in the concentration of cytokines after exposure to Cd and EtOH alone and in combination.