Antioxidant-Based Therapy Reduces Early-Stage Intestinal Ischemia-Reperfusion Injury in Rats

Abstract

Intestinal ischemia-reperfusion injury (i-IRI) is a rare disorder with a high mortality rate, resulting from the loss of blood flow to an intestinal segment. Most of the damage is triggered by the restoration of flow and the arrival of cytokines and reactive oxygen species (ROS), among others. Inactivation of these molecules before tissue reperfusion could reduce intestinal damage. The aim of this work was to analyze the preventive effect of allopurinol and nitroindazole on intestinal mucosal damage after i-IRI. Wag/RijHsd rats were subjected to i-IRI by clamping the superior mesenteric artery (for 1 or 2 h) followed by a 30 min period of reperfusion. Histopathological intestinal damage (HID) was assessed by microscopic examination of histological sections obtained from injured intestine. HID was increased by almost 20% by doubling the ischemia time (from 1 to 2 h). Nitroindazole reduced HID in both the 1 and 2 h period of ischemia by approximately 30% and 60%, respectively (p < 0.001). Our preliminary results demonstrate that nitroindazole has a preventive/protective effect against tissue damage in the early stages of i-IRI. However, to better understand the molecular mechanisms underlying this phenomenon, further studies are needed.

Keywords: allopurinol; animal model; antioxidant treatment; intestinal ischemia-reperfusion injury; nitroindazole.

Figure 1

Pathophysiology of mesenteric ischemia reperfusion syndrome (i-IRI). cAMP (cyclic adenosine monophosphate), PMNC (polymorphonuclear cells), ROS (reactive oxygen species). The upward pointing arrow (↑) signifies increase, and The downward pointing arrow (↓) signifies decrease.

Figure 2

View of the surgical field: (a) anatomical location of the main structures: CV (cava vein), LRV (left renal vein), CT (celiac trunk), and SMA (superior mesenteric artery), the asterisk indicates the site of placement of the microvascular clip; (b) detail of the dissected SMA with the microvascular clip.

Figure 3

Representative photomicrographs of small intestine sections stained with hematoxylin/eosin. Animals subjected to a period of 1 (a–c) or 2 h (d–f) of ischemia, followed by 30 min of reperfusion. The photographs on the left (a,c) correspond to histological sections obtained from untreated animals, the photographs in the center (b,d) to animals treated with allopurinol and the photographs on the right (c,f) to animals treated with nitroindazole.

Figure 4

Pharmacological modulation of the histological injury degree (HID) after treatment with allopurinol (grid pattern) or nitroindazole (line pattern), after 1 (white) or 2 h (grey) of ischemia. ***: p < 0.001; ^###: p < 0.001; ns: p > 0.05. The dashed line indicates the HID score of the control non-ischemic tissue. Non-relevant data (vehicle groups) have been excluded from the figure.