Figure 1.

Lipopolysaccharide (LPS) produces a robust but transient increase in plasma TNFα and CCL2. Plasma was sampled at the time of sacrifice from aged Fisher 344 rats 2, 24, and 48 h after administration of 50 μg/kg LPS (N = 5 per group) or a control group (N = 5) that received an equal volume of saline intraperitoneally. There was a marked increase in both TNFα (A) and CCL2 (B) 2 h after LPS but the effect resolved completely by 24 or 48 h, respectively. Data are mean ± SEM. ***P < 0.001 by one-way ANOVA.