Study on the relationship between cadmium chloride-induced adrenocortical cell of guinea pig apoptosis and stress-activated protein kinase activity

Heavy metals are important environmental pollutants that affect many cellular functions. The signaling pathways that lead to apoptosis of adrenocortical cells following exposure to cadmium chloride (CdCl2) have not yet been fully clarified. We developed a primary culture of guinea pig adrenocortical cells and treated it with various concentrations of CdCl2 for different time periods. The apoptosis induced by CdCl2 was detected by fluorescein isothiocyanate-labeled annexin V and propidium iodide staining using a flow cytometer. Stress-activated protein kinase (SAPK) activities were measured by immunoprecipitation and chemiluminescence assay. After 2 h of treatment, the apoptotic cell rate increased in a dose-dependent manner. The difference between the high-dose group and the control group was significant (P<0.01). The apoptosis was also found to increase in a time-dependent manner in cells treated with 50 μmol/L CdCl2. Among the various treatment period groups, the difference between more than 1 h-treated groups and the control group was significant (P<0.01). The SAPK activity increased with an increase in CdCl2 dose after 5 min of exposure. However, after 15 min of exposure to CdCl2, the SAPK activity decreased with an increase in exposure time. Our findings suggest that the SAPK signaling pathway might play an important role in CdCl2-induced apoptosis of adrenocortical cells.