1 Animal models
All experimental rabbits were successfully modelled. Delayed angiography under DSA showed that blood flow in the lower abdominal aorta below the level of balloon occlusion was completely interrupted, as there was no contrast agent visible below the balloon catheter (Figure 1).
2 Liver and kidney function indicators
After the aortas were occluded for the indicated times in each group, the BUN levels in groups IV and V were 7.93 ± 1.12 mmol/L and 9.67 ± 1.63 mmol/L, respectively, which were significantly higher than those in group I (4.93±0.39 mmol/L, P<0.05 for both). The Scr levels in groups IV and V were significantly higher than those in group I (58.86 ± 8.21 and 68.71 ± 5.82 mmol/L vs 50.0±3.91 mmol/L; P<0.05 for both). AST levels in groups IV and V increased significantly to 60.8±9.44 U/L and 76.85 ± 6.59 U/L, respectively, compared with that in group I (21.28 ± 4.03 U/L; P<0.01 for both). The ALT levels in groups III, IV and V were 29.0 ± 1.82 U/L, 52.14 ± 4.37 U/L, and 80.28 ± 4.99 U/L, respectively, which were significantly higher than that in group I (24.71±4.27 U/L; P <0.05 for all; Figure 2).
3 Inflammatory factors
After 2 h of reperfusion, the IL-6, IL-8, and TNF-α levels in groups III, IV and V were all increased compared with those in group I. The concentrations of IL-6 in groups III, IV and V were 24.6±1.73 pg/mL, 34.41±3.33 pg/mL and 42.58±3.14 pg/mL, compared with 15.41±1.0 pg/mL for group I (P <0.01 for all); the IL-8 concentrations in groups III, IV, and V were 172.15±20.65 pg/mL, 209.15±27.3 pg/mL, 289.03 ± 18.69 pg/mL, respectively, compared with 85.62±9.66 pg/mL for group I (P<0.01 for all); and the TNF-α concentrations in groups III, IV and V were 182.28±17.72 pg/mL, 232.43±19.32 pg/mL and 323.86±13.47 pg/mL, respectively, compared with 127.14±10.23 pg/mL for group I (P<0.01 for all; Figure 3).
4 Oxidative stress indicators among groups
The MDA levels in groups III, IV and V increased to 3.17±0.28 nmol/mL, 3.59±0.23 nmol/mL and 4.91±0.28 nmol/mL, respectively, compared with the level in group I (1.61±0.12 nmol/mL; P <0.01 for all); however, the SOD levels in groups III, IV and V gradually decreased to 138.0±13.21U/mL, 112.71±7.47U/mL and 87.0±9.63U/mL, in comparison with the level in group I (163±6.74 U/mL), and the difference was statistically significant (P <0.01 for all; Figure 4).
5 The pathology of kidney tissue
The kidney tissue structure in groups I and II was clear, with the structure of the glomerular cells and renal tubular cells showing mainly normal features. In group III, mild swelling of glomerular cells and diffuse swelling of renal tubular cells were observed. In group IV, severe diffuse swelling and some necrosis of the renal tubular cells was observed, and moderate to severe swelling of glomerular cells was seen. In group V, the degree of swelling of the glomerular cells and renal tubular cells was more severe, and haemorrhage was present in the renal interstitium (Figure 5).
6 The expression levels of IL-6, IL-8, TNF-α and NF-κB mRNA in kidney and uterine tissues
6.1 Kidney tissues: IL-6 mRNA levels in groups III, IV and V were 1.267±0.052, 2.221±0.258 and 2.749±0.142, respectively, compared with those in group I (0.884±0.026), the differences were statistically significant (P<0.01 for all). IL-8 mRNA levels in groups III, IV and V were higher than those in group 1 (1.402±0.073, 2.056±0.241 and 2.269±0.374, respectively, vs. 0.857±0.126), and the differences were statistically significant (P<0.05, all). TNF-α mRNA levels in groups III, IV and V were 1.486±0.105, 1.987±0.211 and 2.954±0.176, respectively, which were higher than those in group I (0.823±0.089), and the differences were statistically significant (P<0.05, all). Finally, the NF-κB mRNA levels in groups III, IV and V were 1.636±0.279, 2.330±0.643 and 3.243±0.274, which were higher than those in group I (0.958±0.069), the differences were statistically significant (P<0.05 for all). The data are summarized in Figure 6.
6.2 Uterine tissues: The IL-6 mRNA levels in groups III, IV and V were 1.278±0.088, 1.635±0.174 and 2.028±0.091, respectively, which were higher than those in group I (0.947±0.084), and the differences were statistically significant (P<0.05 for all). IL-8 mRNA levels in groups III, IV and V were 1.357±0.159, 1.852±0.121 and 2.232±0.103, respectively, which were higher than those in group I (0.979±0.041), and the differences were statistically significant (P<0.05, all). TNF-α mRNA levels in groups III, IV and V were 1.470±0.208, 1.626±0.242 and 2.113±0.069, respectively, which were higher than those in group I (0.987±0.062), and the differences were statistically significant (P<0.05, all). Finally, NF-κB mRNA levels in groups III, IV and V were 1.770±0.118, 2.105±0.097 and 2.542±0.098, respectively, which were higher than those in group I (0.944±0.073), and the differences were statistically significant (P<0.05 for all). The data are summarized in Figure 7.
7 The protein expression levels of IL-6, IL-8, TNF-α and NF-κB in the kidney and uterine tissues
7.1 Kidney tissues: IL-6 protein expression in groups III, IV and V was 0.446±0.064, 0.592±0.046 and 0.673±0.062, respectively, which was higher than that in group I (0.317±0.024), and the differences were statistically significant (P<0.05 for all). IL-8 protein expression in groups III, IV and V was 0.427±0.007, 0.581±0.021 and 0.640±0.165, respectively, which was higher than that in group I (0.301±0.029), and the differences were statistically significant (P<0.05 for all). TNF-α protein expression in groups III, IV and V was 0.583±0.090, 0.738±0.070 and 0.844±0.086, respectively, which was higher than that in group I (0.342±0.067), and the differences were statistically significant (P<0.05 for all). Finally, NF-κB protein expression in groups III, IV and V was 0.556±0.051, 0.713±0.068 and 0.802±0.079, respectively, which was higher than that in group I (0.314±0.039), and the differences were statistically significant (P<0.05 for all). The data are summarized in Figure 8.
7.2 Uterine tissues: IL-6 protein expression in groups III, IV and V was 0.284±0.425, 0.426±0.055 and 0.487±0.091, respectively, which was higher than that in group I 0.154±0.034, and the differences were statistically significant (P<0.05 for all); IL-8 protein expression in groups III, IV and V was 0.179±0.033, 0.286±0.013 and 0.349±0.032, respectively, which was higher than that in group I (0.118±0.016), and the differences were statistically significant (P<0.05 for all). TNF-α protein expression in groups III, IV and V was 0.537±0.025, 0.661±0.038 and 0.773±0.024, respectively, which was higher than that in group I (0.329±0.001), and the differences were statistically significant (P<0.05 for all). Finally, NF-κB protein expression in groups III, IV and V were 0.666±0.033, 0.892±0.041 and 0.979±0.039, respectively, which was higher than that in group I (0.454±0.009), and the differences were statistically significant (P<0.05 for all). The data are summarized in Figure 9.