Figure 1.

CBG reduces the plasma clearance of corticosterone. A, Mean ± SEM plasma [³H]-corticosterone counts per minute (CPM) in male and female rats with and without CBG, after intravenous injection of [³H]-corticosterone. In both sexes, 2-way ANOVA revealed main effects of time (F's ≤ 124.3; P's < .0001) and genotype (F's ≤ 26.55; P's < .0391) and an interaction between time and genotype (F's ≤ 30.16 P's < .0001). B, Slope profiles revealed a faster clearance rate in female compared to male wild-type (P = .007), and the clearance rate tended to be faster in female compared to male CBG-knockout rats (P = .1). C, Average CPM values from CBG-knockout rats were subtracted from individual wild-type CPM values to isolate the effect of CBG. The slopes were not different between males and females (P = .6). N = 3 per group. M = male, F = female, WT = wild-type, KO = CBG-knockout.