GENE EXPRESSION AND ULTRASTRUCTURAL CHANGES IN MULTIPLE ORGANS AFTER SMALL BOWEL ISCHEMIA-REPERFUSION IN RATS

Li Cao¹, Peng Chen², Fengxia Gong², Guanglong Dong^{2, *}

¹School of Medicine, Nankai University, Tianjin 300071, China - ²Department of General Surgery, First Medical Center of PLA General Hospital, Beijing 100853, China

Purpose: Small-bowel ischemia and reperfusion may cause damage to multiple organs. This study mainly explores related gene expression and ultrastructural changes in multiple organs of rats, after small-intestine ischemia-reperfusion.

Methods: After anesthetizing and fixing each rat on the operating panel, aseptic operation procedures were followed. After disinfection, a midline incision of about 3 cm was cut in the lower abdomen, near the xiphoid process. Using warm saline gauze, the small intestine and colon were pushed to the left lower abdomen, the SMA was clamped for 45 min, and the abdomen was then closed. After conducting reperfusion for 2 h and 4 h, the abdomen was reopened to collect specimens. In each rat, a 6 cm length of the small intestine tissue 50cm from the blind area was cut along the longitudinal axis. The water in the intestinal cavity was absorbed by absorbent paper and wet weight (W) of the sectioned small intestine tissue was measured and recorded; the tissue was then placed at a constant temperature of 80°C. Next, after 24 h in an incubator, the dry weight (D) was measured and recorded. After 2 min of reperfusion, 2ml of blood was extracted, utilising EDA anticoagulant, from the main abdominal vein. After centrifugation at 3500 rpm and 4°C for 15 min, the supernatant was stored at –70°C. Next, after being placed at low temperature for 30 s, the supernatant was centrifuged immediately at 4°C for 30 minutes, and stored in a freezer at –70°C for measurement of TNF-a. A selection of the intestinal bag specimens were also fixed in 10% formalin solution.

Results: After HE staining, the mucosal damage was observed under a microscope and scored. The XOD activity of the IP group (39.01±4.64U/mg) was significantly lower than that of the other ischemic injury groups, and was significantly lower than that of the placebo group (46.59±4.20U/mg, p<0.05). The rat villi epithelium was destroyed and shedding, and the morphological structure of each organ was seriously damaged.

Conclusion: The results of this study indicate that in rats, small-intestine ischemia/reperfusion can cause lung tissue damage, and can promote the expression of Bc1-2.