Exacerbation of LPS-induced fever by central MCR blockade. Rats were treated with LPS (25 μg/kg, i.p.) or with saline at time 0 (arrow), and with the indicated intracerebroventricular injectates 30 min later (arrow).A, Time course of LPS-induced fever in the presence and absence of intracerebroventricular SHU-9119 (200 ng). Also shown areTb profiles of rats receiving comparable intracerebroventricular infusions after intraperitoneal injection of saline rather than LPS. Numbers of animals in each group are indicated in parentheses. Baseline Tbvalues for the four respective treatment groups were (°C) LPS/SHU-9119 (•), 37.5 ± 0.1; LPS/NaCl (○), 37.7 ± 0.1; NaCl/SHU-9119 (▴), 37.5 ± 0.2; NaCl/NaCl (▵), 37.6 ± 0.1. B, Data from A represented as areas under the temperature-time response curves. By two-way ANOVA, significance of main effects for LPS and for SHU-9119, respectively, are F(1,23) = 79, p < 0.0001, and F(1,23) = 22,p < 0.0001; F(1,23) = 10, p = 0.004 for interaction. Statistical significance of between-group comparisons is indicated in the figure.