Serum levels of TNF-α and IL-10 in mice challenged with PAF in the presence and absence of LPS.

<p>(<b>a</b>, <b>b</b>) Blood was collected from the animals injected with PAF alone (5 μg/mouse) or with 5 mg/kg LPS + PAF (5 μg/mouse) 7 min after challenge, whereas blood was collected 4 h after challenge for the other animals. Serum was then separated from the blood for analysis. The levels of TNF-α (a) and IL-10 (b) were measured using ELISA kits, as per the manufacturer’s instructions. The insets show the TNF-α and IL-10 levels for the mice injected with vehicle or PAF (5 μg/mouse) or 5 mg/kg LPS + PAF. All values are expressed as pg/mL and presented as mean ± SD (n = 3). <i>*P</i><0.05; **<i>P</i><0.01, as compared with mice injected with vehicle. LPS cross-tolerance to PAF-induced sudden death neither increased the level of circulating anti-inflammatory IL-10 nor decreased the level of pro-inflammatory TNF-α.