Prostaglandin E-major urinary metabolites as a new biomarker for acute mesenteric ischemia

Abstract

BACKGROUND Acute mesenteric ischemia (AMI) is an emergent vascular disease caused by cessation of the blood supply to the small intestine. Despite advances in the diagnosis, intervention, and surgical procedures, AMI remains a life-threatening condition. Prostaglandin E2 major urinary metabolite (PGE-MUM), the urinary metabolite of prostaglandin E2, is known to be stable in urine and has been suggested to be a valuable biomarker for intestinal mucosal inflammation, such as ulcerative colitis. We therefore investigated whether or not PGE-MUM levels reflect the degree of ischemia in an intestinal ischemia-reperfusion model. METHODS Male rats were used to establish a superior mesenteric artery occlusion (SMAO) group, in which the superior mesenteric artery was clamped, and a sham group. The clamping times in the SMAO group were either 30 minutes or 60 minutes, and reperfusion times were either 3 hours or 6 hours, after which PGE-MUM values were measured. RESULTS The histological injury score of the SMAO (30-minute ischemia and 6-hour reperfusion group, 1.8 ± 0.4; 60-minute ischemia and 6-hour reperfusion group, 4.7 ± 0.5) and were significantly greater than that of the sham group (0.4 ± 0.7, p < 0.05). The PGE-MUM levels in the SMAO group (30-minutes ischemia and 6-hour reperfusion group, 483 ± 256; 60-minutes ischemia and 6-hour reperfusion group, 889 ± 402 ng/mL) were significantly higher than in the sham group (30-minute and 6-hour observation group, 51 ± 20; 60-minute and 6-hour observation group, 73 ± 32 ng/mL; p < 0.05). Furthermore, the PGE-MUM value was corrected by the concentration of urinary creatinine (Cr). The PGE-MUM/urinary Cr levels in the SMAO group were also significantly higher than in the sham group (p < 0.05). CONCLUSION We found that intestinal ischemia-reperfusion increased urinary PGE-MUM levels depending on the ischemic time. This suggests the potential utility of PGE-MUM as a noninvasive marker of intestinal ischemia.