Effects of control (vehicle, VEH) or stress hormones, norepinephrine (NE), epinephrine (EPI), corticosterone (CORT), NE+EPI, NE+CORT, EPI+CORT, and NE+EPI+CORT (bars shown in this order) on WBC, monocyte, neutrophil, lymphocyte, and Th, CTL, B, and NK cell numbers in the blood. Leukocyte numbers (1000 /μl blood) were quantified 2 hours after vehicle or hormone injection in adrenalectomized animals. An increase in immune cell numbers relative to the VEH group represents mobilization of leukocytes into the blood. A decrease represents trafficking of cells out of the blood and into tissues. Data are expressed as means ± SEM (n=3 or 4 per treatment group). Statistically significant differences are indicated: * p < 0.05, and ** p < 0.01: relative to baseline (Fisher's LSD); † p < 0.05, and †† p < 0.01: please see text for comparison groups (Fisher's LSD).