Superior mesenteric artery occlusion leads to mesenteric ischemia, activation of arachidonic acid metabolism and release of endotoxins into the systemic circulation. The effect of leukotriene and prostaglandin antagonists on hemodynamic response and survival of rats after superior mesenteric artery (SMA) occlusion was investigated. The animals were divided into five groups: in group 1 (n = 105) the SMA was clamped for 2 h and mortality assessed after 24 h. Group 2 animals (n = 20) were pretreated with 5 mg/kg indomethacin and the SMA clamped similarly to group 1, group 3 animals (n = 15) were pretreated with 5 mg/kg Voltaren, group 4 animals (n = 20) received 20 mg/kg BW 755C before mesenteric artery occlusion, and group 5 animals (n = 50) were pretreated with 100 mg diethylcarbamazine. The blood pressure and pulse response as well as histologic appearance of the bowel 1 h after declamping was similar in all five groups. The mortality rate after 24 h was 34% in the control group, 36% with indomethacin treatment, 36% with voltaren, 47% with BW 755C and 40% with diethylcarbamazine. The mortality rate in all the treated groups was not significantly different from the control group. Plasma thromboxane B2 levels were inhibited significantly by indomethacin and Voltaren and to a lesser extent by BW 755C. There was a paradoxical rise in thromboxane B2 following diethylcarbamazine treatment. It is concluded that inhibition of the cyclooxygenase and/or the Hpoxygenase pathways of arachidonic acid did not alter the hemodynamic response and mortality following 2 h of acute superior mesenteric artery occlusion.