LPS-induced decrease of specific binding of 3H-dexamethasone to peritoneal macrophages of C57BL/6 mice.

The effect of LPS on the specific binding of 3H-dexamethasone to peritoneal macrophages of C57BL/6 mice was studied. Scatchard plot of the specific binding of 3H-dexamethasone to the macrophages indicated that the Kd and Ro of glucocorticoid receptor was approximately 3.0 nM and 5,500 binding sites per cell, respectively. LPS, at the concentration of 10 ug/ml, caused a decrease in the specific binding of 3H-dexamethasone to macrophages after it interacted with the macrophages for different times. Con A, a mitogen for lymphocytes, did not significantly cause a decrease of glucocorticoid receptor in the macrophages at the concentration of 10 ug/ml. Our results indicated that the effect of LPS on the specific binding of 3H-dexamethasone to macrophages was different from the effect of Con A, which might be significant in the interaction of immune system and neuroendocrine system.