This study was conducted to examine the effects of peptidoleukotrienes on the ileal contractility disturbances induced by Serratia marcescens endotoxin in rats. Thirty-two male Wistar rats were divided into four groups (n = 8 each). The first group was given only an anesthetic agent (control group); the second group was given the endotoxin (endotoxin group); the third group was given a lipoxygenase inhibitor, nordihydro-guaretic acid (NDGA); and the fourth group was given NDGA 10 min before administration of the endotoxin (NDGA + endotoxin group). The isolated ileum response was recorded in each group. Normal contractile activity was seen in the control group. After the endotoxin was given, the isolated ileum did not respond to 497 acetylcholine (ACh) in the endotoxin group, but the contractile results of isolated ileum to ACh were similar to the control group results in both the NDGA and endotoxin + NDGA groups. The results of this study demostrate that leukotrienes may play a low in endotoxin-induced ileal contractility disturbances, and that the lipoxygenase inhibitor, NDGA, could be useful for the treatment of ileal motility disturbances induced by endotoxin.