Alanine-glutamine dipeptide pretreatment protects rat renal function from small intestine ischemia-reperfusion injury.

AIM: Oxidative injury can cause renal function impairment and failure. Glutathione, a free radical scavenger, plays in the kidney a central role in oxidant-related events. The aim of this study was to investigate the potential beneficial effect of glutamine, a precursor of glutathione in the form of alanine-glutamine dipeptide (AGD) on small intestine ischemia/ reperfusion (I/R)-induced oxidant renal damage in rats. METHODS: Wistar rats were subjected to intestinal I/R for 30 min, induced by occlusion of the superior mesenteric artery, followed by 60 min reperfusion. AGD pretreatment was given 48 and 24 hours before I/R. At the end of the experimental procedure the left kidney was excised and a thin tissue slice was obtained for electron microscopy study. Kidney biopsies were obtained for malonyl dialdehyde, myeloperoxidase, and glutathione assays. RESULTS: Intestinal I/R caused significant oxidative injury in rat renal parenchyma consisted of severe alterations observed in subcellular renal structures associated with a significant increase in renal malonyl dialdehyde levels and a significant decrease in renal glutathione levels. Changes regarding subcellular renal structures were ameliorated in AGD pre-treated animals in which renal glutathione levels did not decreased significantly. CONCLUSION: Glutamine pretreatment in the form of AGD can prevent small bowel I/R-induced oxidant renal damage in rats.

Effect of early postoperative enteral feeding on the healing of colonic anastomoses in rats. Comparison of three different enteral diets.

This experimental study compares the effects of early postoperative administration of three enteral diets of different compositions on the healing of colonic anastomoses. Sixty Wistar rats were subjected to colonic anastomoses. Following surgery, the rats were randomly allocated to four groups of 15 each. The rats in control group A received an electrolyte and glucose solution, the rats in group B received a complete balanced nutrition, in group C a complete balanced nutrition supplemented with fiber and in group D an isocaloric specialized elemental nutrition enriched with glutamine. The rats were sacrificed on day 7 following operation. Rupture of the anastomosis was higher in rats of the control group compared to the other three groups. Adhesion formation was more extensive in group A in comparison to the other three groups. The anastomotic bursting pressures were statistically significantly higher in groups C and D compared to the other two groups (p < 0.05). There was no statistically significant difference between group C and D (p > 0.05) while a statistically significant difference was noted between group B and group A (p < 0.05). Histological examination showed more profound inflammatory reaction in group A compared to the other three groups. There was also a statistically significant difference between group B and groups C and D while inflammatory reaction was of no statistically significant difference between group C and group D. Healing of the anastomoses was statistically significantly impaired in group A compared to the other three groups. There was no statistically significant difference between group C and group D while a statistically significant difference was found between group B and groups C and D. In conclusion, early postoperative enteral feeding improves healing of experimental colonic anastomoses in rats. This effect was more evident when fiber-supplemented diets or diets enriched with glutamine were administered.

Effect of early versus delayed postoperative injection of 5-fluorouracil plus interferon-alpha on colonic healing.

The purpose of this study was to determine whether delayed, postoperative, intraperitoneal treatment with 5-fluorouracil (5-FU) plus interferon-alpha-2a (IFN) has adverse effects on colonic healing, as does early treatment. Seventy male Wistar rats underwent colonic anastomoses. The rats were randomized to one of four groups. Early intraperitoneal injection was given to groups 1 and 2 which was repeated once daily for the first 3 postoperative days. Treatment was delayed in groups 3 and 4, from the 4th to the 7th postoperative day. A 0.9% NaCl solution was injected in the rats of control groups 1 and 3. In groups 2 and 4, we infused 5-FU (20 mg/kg/day) and IFN (45,000 IU/kg/day). All the animals were sacrificed on the 8th postoperative day. The anastomotic rupture rate was significantly higher in the rats of group 2 compared to control group 1 (p < 0.05), while there were no differences between groups 3 and 4 (p > 0.05). Abscess formation and adhesions were more frequent in group 2 compared to control group 1, while no differences were observed between groups 3 and 4. Anastomotic bursting pressure was statistically significantly lower in the rats of group 2 compared to group 1 (p < 0.05); no differences were noticed between groups 3 and 4 (p > 0.05). Simultaneous histologic evaluation showed a more profound inflammatory reaction and delayed anastomotic healing in group 2 compared to control group 1; there were, however, no differences between groups 3 and 4. In conclusion, the immediate, postoperative, intraperitoneal injection of 5-FU plus IFN impairs colonic healing while delayed treatment (starting on the 4th postoperative day) has no adverse effects on wound healing.