Superior mesenteric artery occlusion shock in cats: modification of the endotoxemia by antilipopolysaccharide antibodies (anti-LPS).

We measured the time course of elevated plasma LPS concentration caused by a temporary intestinal ischemia using the superior mesenteric artery (SMA) occlusion shock model in anesthetized cats. The systemic plasma LPS increased from 0.075 +/- 0.006 ng/cc to 0.219 +/- 0.026 ng/cc (P less than 0.001) during the occlusion period. On release of the clamp, the plasma LPS concentration rose rapidly to 0.716 +/- 0.122 ng/cc (P less than 0.001) within 20 min. Thereafter, it declined to reach baseline levels after 100-120 min reperfusion. A total of 21 animals received IV 1.0 cc/kg antilipopolysaccharide hyperimmune equine plasma (anti-LPS) either 1.5 hr before the occlusion or at 0, 10, or 20 min after release of the occlusion. Prophylactic anti-LPS prevented any rise in plasma LPS both during and after release of the occlusion. The administration of anti-LPS during the reperfusion period completely reversed the endotoxemia caused by intestinal ischemia within 5-10 min. This rapidity of response to anti-LPS may be important in the previously reported therapeutic benefit of anti-LPS.