Effects of Corticosterone on Immune Functions of Cultured Rat Splenic Lymphocytes Exposed to Aluminum Trichloride.

Aluminum (Al) exposure is toxic to immune system. Studies have implicated that glucocorticoids (GCs) exert the dual regulation effect on the immune function depending on the concentration. However, it is unknown whether a dual effect of GCs exists in the AlCl-treated lymphocytes. Corticosterone (Cort) is one kind of GCs. To investigate the effect of different concentration Cort on AlCl-treated lymphocytes, rat splenic lymphocyte was isolated and cultured with 0.55 mmol/L AlCl, simultaneously administrated Cort at final concentration of 0 (control group, CG), 10 (low-level group, LG), and 10 (high-level group, HG) mol/L, respectively. Another group without AlCl and Cort served as the blank group (BG). We found that low concentration Cort increased the T and B lymphocyte proliferation rate, proportions of CD4 T lymphocyte subset, IgG, IL-2, and TNF-α contents, whereas high concentration Cort decreased those in AlCl-treated lymphocytes. In conclusion, the results of this study indicated that low concentration Cort relieves the immunotoxicity of AlCl on the splenic lymphocytes, whereas high concentration Cort aggravates it. [ABSTRACT FROM AUTHOR]