Figure 4. Effects of IL-1ra treatment on baseline plasma CORT concentration and on DEX/CRH test.

Since in all three groups of naïve animals all examined parameters were statistically similar for the first and the second assays, in order to simplify the presentation of the findings, the outcome of DEX/CRH test is presented only for the second assay (i.e. during IL-1ra treatment) and data in naive groups are combined for the three treatments (i.e. IL-1ra, saline, and untreated). In saline-treated and untreated rats, SE led to the increase of baseline plasma CORT level; failure of DEX to decrease CORT concentration; and the exacerbated and longer-lasting response to CRH (since the responses in two groups were statistically close, the data are combined for presentation purposes). IL-1ra decreased baseline plasma CORT level and partially normalized the outcome of DEX/CRH test. Data are presented as Mean±SEM. Even though data for some groups were combined, statistical comparisons were done between respective groups: #- p<0.05 Post-SE-Saline and Post-SE untreated vs. respective Naïve controls and at respective time points; †- p<0.05 post-SE IL-1ra vs. Naive IL-1ra; ‡- p<0.05 post-SE IL-1ra vs. post-SE Saline and post-SE untreated (One-Way ANOVA + Neuman-Keuls post hoc test). *- p<0.05; **- p<0.01; ***- p<0.001 comparison within the same groups, for two adjacent time points between which the symbols are located (Repeated measure ANOVA + Neuman-Keuls post hoc test).