Plasma D (-)-lactate as a new marker for diagnosis of acute intestinal injury following ischemia-reperfusion

Abstract

To observe the kinetics of D (-)-lactate alteration in both portal and systemic circulation systems, and its relationship with intestinal injury in rats subjected to acute intestinal ischemia-reperfusion. Anesthetized rats underwent a 75-min superior mesenteric artery occlusion followed by a 6-h reperfusion. Plasma D (-)-lactate levels were measured by an enzymatic spectrophotometric assay. Intestinal ischemia for 75 min resulted in a significant elevation of D (-)-lactate levels in the portal vein, as compared with the baseline values (P < 0.05). Plasma D (-)-lactate levels had a tendency to further increase after reperfusion, up to 6 h. Similar alterations in D (-)-lactate were also found in systemic circulation, and there were no significant differences between the portal and systemic circulations at any time point. Moreover, the macropathological evaluation scores were significantly correlated to the portal D (-)-lactate levels in animals at various time points (r = 0.415, P < 0.01). In addition, there was a remarkable rise of endotoxin concentration within the portal vein at the end of the 75-min ischemic period (P < 0.05), reaching a peak at 2 h post-reperfusion. Acute intestinal ischemia is associated with failure of the mucosal barrier resulting in increased plasma D (-)-lactate levels in both portal and systemic blood. The subsequent reperfusion might further increase D (-)-lactate levels, which are correlated to the macropathological alterations. Plasma D (-)-lactate may be a useful marker of intestinal injury following both ischemia and reperfusion insults.