Characterization and evolution of intestine injury at the anhepatic phase in portal hypertensive rats

Abstract

The aim of the present study was to investigate the characteristics and progression of intestinal injury at the anhepatic phase in portal hypertensive rats. A total of 120 healthy male Wistar rats were purchased, with 15 rats in the normal control group and 105 rats were assigned to establish a prehepatic portal hypertension model. The 105 model rats were further divided into seven treatment groups following ischemia-reperfusion. Meanwhile, portal vein pressure, the area of lower esophageal mucosal vein, endotoxin levels in portal vein blood and the level of malondialdehyde (MDA) and superoxide dismutase (SOD) were measured. Morphology changes of the intestine were observed using optical microscopy and transmission electron microscopy. A portal hypertension rat model was successfully established. Furthermore, endotoxin, MDA and SOD level reached a peak at 12-24 h following reperfusion and then decreased gradually to normal levels at 1 week following reperfusion. However, cytological damage did not recover to preoperative level within 1 week. These findings suggest that intestinal injury was most severe within 12-24 h following ischemia-reperfusion and most indicators recovered to almost normal levels. Therefore, further study on the intestinal mucosal damage is required, with the aim to reduce the production of intestinal endotoxin.

Keywords: anhepatic phase; intestine injury; ischemia-reperfusion; liver transplantation; portal hypertension rat model.

Figure 1.

Measurement of (A) arterial blood pressure and (B) area of lower esophageal mucosal vein. Arterial blood pressure was monitored using BIOPAC systems. Data are presented as the mean ± standard deviation of three replicate experiments. *P<0.05 vs. normal group.

Figure 2.

Analysis of endotoxin in portal vein blood. Data are presented as the mean + standard deviation of three replicate experiments. *P<0.05 vs. NCG; ^#P<0.05 vs. PHCG. NCG, normal control group; PHCG, portal hypertension control group; I/R, ischemia reperfusion; I/R0hG, I/R 0 h group; I/R12hG, I/R 12 h group; I/R24hG, I/R 24 h group; I/R48hG, I/R 48 h group; I/R72hG, I/R 72 h group; I/R1wG, I/R 1 week group.

Figure 3.

Analysis of (A) MDA and (B) SOD level. Data are presented as the mean + standard deviation of three replicate experiments. *P<0.05 vs. NCG; ^#P<0.05 vs. PHCG. MDA, malondialdehyde; SOD, superoxide dismutase; NCG, normal control group; PHCG, portal hypertension control group; I/R, ischemia reperfusion; I/R0hG, I/R 0 h group; I/R12hG, I/R 12 h group; I/R24hG, I/R 24 h group; I/R48hG, I/R 48 h group; I/R72hG, I/R 72 h group; I/R1wG, I/R 1 week group.

Figure 4.

Histopathological analysis of intestine tissues with hematoxylin-eosin staining. (A) Normal control group; magnification, ×200; (B) portal hypertensive control group; magnification, ×100; (C) I/R 0 h group; magnification, ×400; (D) I/R 12 h group; magnification, ×200; (E) I/R 24 h group; magnification, ×400; (F) I/R 48 h group; magnification, ×400; (G) I/R 72 h group; magnification, ×400; (H) I/R 1 week group; magnification, ×400. I/R, ischemia reperfusion.

Figure 5.

Cell ultrastructure analysis of intestine tissues. The ultrastructure of intestinal mucosal cells was observed by transmission electron microscopy. (A) Normal control group; original magnification, ×20,000; (B) portal hypertensive control group; original magnification, ×10,000; (C) I/R 0 h group; original magnification, ×20,000; (D) I/R 12 h group; original magnification, ×10,000; (E) I/R 24 h group; original magnification, ×6,000; (F) I/R 48 h group; original magnification, ×20,000; (G) I/R 72 h group; original magnification, ×10,000; (H) I/R 1 week group; original magnification, ×5,000. I/R, ischemia reperfusion.