LPS cross-tolerance to PAF-induced lethality in Swiss albino mice is temporal.

Mice were divided into 6 groups containing 6 animals per group. PAF (5 μg/mouse) was intraperitoneally injected together with LPS (20 mg/kg body wt) or at 30 min, 3 h, or 6 h after LPS was injected. All the animals injected with PAF alone (5 μg/mouse) or at 3 h or 6 h after receiving LPS (20 mg/kg) died in 15–20 min. In the group that received PAF concomitantly with LPS (20 mg/kg body wt), 33.4% of the animals died within 24 h, and 66.6% survived for 6 days. In the group that received PAF (5 μg/mouse) 30 min after LPS (20 mg/kg) was administered, the time until death was delayed to 12–24 h. All the animals were monitored for survival for up to 6 days. The results are representative of 3 individual trials.