Effects of glucocorticoid and antiglucocorticoid hormones on leukocyte numbers and function.

Hormones were administered to mice in seven daily intraperitoneal injections of saline suspensions. Progesterone and cortexolone, which often fail to act as antiglucocorticoids in vivo, were found to have antiglucocorticoid effects on the immune system under these conditions. The effects seen were increases in numbers of lymphocytes, monocytes, neutrophils and total leukocytes in the blood, increases in the number of peritoneal exudate cells and splenic plaque-forming cells, and increased splenocyte responses to the mitogen phytohemagglutinin. Deoxycorticosterone, sometimes also considered to be an antiglucocorticoid, acted only as a glucocorticoid here. Both deoxycorticosterone and the glucocorticoid corticosterone had effects opposite to those produced by progesterone and cortexolone on these parameters.