Figure 3.

Effect of 3β-diol pretreatment on HPA axis responses to IL-1β in male control and PNS rats. Control and PNS male rats were treated with either vehicle (oil) or 3β-diol (1 mg/kg, s.c.) 20 and 2 h before IL-1β. After two basal (B) blood samples (at t = −31 and −1 min), all rats were administered IL-1β (500 ng/kg, i.v.) at t = 0 min. Further blood samples were taken 15, 30, 60, and 90 min after IL-1β. Trunk blood was collected at t = 240 min. a, Plasma ACTH concentrations before and after IL-1β challenge: *p < 0.05 versus B values in the same group; #p < 0.005 versus all other groups at the same time point (two-way RM ANOVA). b, Plasma corticosterone concentration before and after IL-1β challenge: *p < 0.003 versus B values in the same group; #p < 0.04 versus all other groups at the same time point (two-way RM ANOVA). Quantification of (c) CRH mRNA expression in the parvocellular division of the PVN (pPVN) 4 h after IL-1β administration. CRH mRNA expression levels are expressed as grain area/PVN area (mm²/mm²); *p < 0.002 versus respective oil group; #p < 0.001 versus control/oil group (two-way ANOVA). In each case values are group mean ± SEM and n = 7–9 rats/group (exact numbers are given in parentheses in the relevant key or within the bars). d, Representative bright-field CRH mRNA ISH autoradiographs of coronal PVN sections from (di) control/oil; (dii) control/3β-diol; (diii) PNS/oil; and (div) PNS/3β-diol groups. Scale bar, 100 μm.