Relationship between apoptosis and activity of protein kinase B in adrenocortical cells induced by cadmium chloride

Abstract

To study apoptosis induced by cadmium chloride (CdCl2) and the alteration in activity of protein kinase B (PKB/Akt) in adrenocortical cells. Fasciculata-glomerulosa (FG) cells of male guinea pigs were dispersed and primarily cultured in vitro. Features of apoptotic cells were observed using combined labeling with annexin-V and propidium iodide (PI) and flow cytometry. The activity of PKB/Akt was determined with immunoprecipitation and the chemiluminescence assay. Apoptosis rate of FG cells increased with dose of CdCl2 two hours after treatment with 6.25-100.00 micromol/L of it, with significant difference in the groups treated with 25.00, 50.00, 100.00, micromol/L of CdCl2, as compared with the control group (P < 0.01). Regression analysis showed that occurrence of apoptosis correlated with the dose of CdCl2 in a dose-response pattern. In the meanwhile, there were obviously elevated percentages of apoptotic cells as the increase in duration of incubation ranging from 5.58% to 73.08% for incubating cells with 50.00 micromol/L of CdCl2, from 15 minutes to 4 hours. Duration of incubating cells with CdCl2 were correlated with occurrence of apoptosis in a time-effect manner. The gray scales of PKB/Akt were manifested to be decreased as the ascending of CdCl2 dosage from 6.25 to 200.00 micromol/L, with the linear correlation. 6.25 to 100.00 micromol/L CdCl2 might elicit apoptosis of adrenocortical cells. Meanwhile, PKB/Akt is decreased.