Seventy male Sprague-Dawley (SD) rats were randomly divided into control group, different
sugar content PDF model groups and corresponding
traditional Chinese medicine intervention groups, with 10 rats in each group.
Peritoneal fibrosis model was reproduced by
intraperitoneal injection of 100 mL×kg-1×d-1 PDF containing 1.5%, 2.5% and 4.25%
sugar once a day for 8 weeks. The rats in the control group were given the same amount of
normal saline. The rats in the
traditional Chinese medicine intervention groups were treated with gavage of 10 mL/kg of modified
Shenling Baizhu San (containing 2.014 g crude
drug per liter) immediately after modeling. The PDF model groups and the control group were given the same amount of
normal saline by gavage. After 8 weeks, the peritoneal ultrafiltration volume of rats in each group was measured. The peritoneal tissues were collected and stained with
hematoxylin-
eosin (HE), and the structural changes and thickness of the parietal peritoneum were observed under a light microscope. After Masson staining, the deposition of
collagen fibers was observed under a light microscope. Western blotting was used to detect the
protein expressions of
E-cadherin, α-smooth muscle actin (α-SMA) and
Vimentin, the main components of ECM in parietal peritoneum. The positive expressions of
matrix metalloproteinase-9 (MMP-9),
tissue inhibitor of metalloproteinase-1 (TIMP-1), and transforming growth factor-β1 (TGF-β1) were detected by immunohistochemical staining.
RESULTS: Compared with the control group, PDF with different
sugar contents could induce
peritoneal fibrosis in rats, and the degree of
fibrosis was gradually aggravated with the increase of
sugar content, which was manifested as peritoneal thickening, increased
collagen fiber deposition, decreased peritoneal ultrafiltration volume, down-regulated expressions of
E-cadherin and MMP-9 in peritoneal tissue, and up-regulated expressions of α-SMA,
Vimentin,
TIMP-1 and TGF-β1, and the pathological changes and ECM accumulation in peritoneal tissues were more serious in 4.25% PDF model group. After the intervention of modified
Shenling Baizhu San, compared with the corresponding PDF model groups, the
peritoneal fibrosis of rats was improved to varying degrees, and the effect of the 4.25% PDF+traditional Chinese medicine intervention group was more significant, the parietal peritoneum was significantly thinner (μm: 101.86±16.01 vs. 140.65±10.13, P < 0.05),
collagen fiber deposition was significantly reduced, peritoneal ultrafiltration volume was significantly increased (mL: -0.01±3.45 vs. -3.53±1.84, P < 0.05), the expressions of
E-cadherin and MMP-9 in peritoneal tissues were significantly up-regulated [
E-cadherin protein (
E-cadherin/β-actin): 0.84±0.08 vs. 0.28±0.05, MMP-9 (A value): 0.60±0.15 vs. 0.37±0.01, both P < 0.05], and the expressions of α-SMA,
Vimentin,
TIMP-1 and TGF-β1 were significantly down-regulated [α-SMA
protein (α-SMA/β-actin): 0.36±0.08 vs. 1.05±0.09,
Vimentin protein (
Vimentin/β-actin): 0.53±0.07 vs. 1.19±0.04,
TIMP-1 (A value): 0.49±0.06 vs. 0.87±0.02, TGF-β1 (A value): 0.67±0.04 vs. 0.89±0.10, all P < 0.05].
CONCLUSIONS: