The Effect of Vitamin D on Peritoneal Adhesion in Rats with Experimentally Induced Peritoneal Surface Damage

AIM: To investigate the effect of 1,25-dihydroxyvitamin D3 on peritoneal adhesion formation in an experimental rat model.
MATRERIAL and METHOD: Twenty-four male Sprague–Dawley rats were randomly divided into three groups: control group (n=8), peritoneal adhesion group (PA; n=8), and peritoneal adhesion plus vitamin D group (PAD; n=8). Peritoneal adhesions were induced using the peritoneal button creation technique in the PA and PAD groups. Rats in the PAD group received 1,25-dihydroxyvitamin D3 at a dose of 12 µg/kg by oral gavage for 14 days, whereas rats in the PA group received vehicle alone. At the end of the experiment, peritoneal tissue and blood samples were collected. Histological fibrosis, inflammation, and vascular proliferation were evaluated using hematoxylin and eosin staining. Fibrin deposition was assessed using PTAH staining, and tissue plasminogen activator (PA) inhibitor-1 (PAI-1) expression was evaluated immunohistochemically. Serum PA and PAI-1 levels were measured by ELISA
RESULTS: Fibrosis scores were significantly lower in the PAD group than in the PA group (2.0±0.5 vs. 3.0±0.0, p=0.001). PTAH scores were also significantly lower in the PAD group than in the PA group (1.1±0.3 vs. 4.0±0.0, p < 0.001), indicating reduced fibrin deposition. Similarly, tissue PAI-1 staining scores were significantly lower in the PAD group than in the PA group (1.9±0.3 vs. 3.0±0.0, p<0.001). Although inflammation and vascular proliferation scores were numerically lower in the PAD group, these differences were not statistically significant (p=0.317 for both). Serum PA and PAI-1 levels did not differ significantly between the PA and PAD groups.
CONCLUSION: In this experimental rat model, 1,25-dihydroxyvitamin D3 administration attenuated peritoneal adhesion-related tissue changes, particularly fibrosis, fibrin deposition, and tissue PAI-1 expression. These findings suggest that vitamin D may have a local protective effect against postoperative peritoneal adhesion formation, although further studies are needed to clarify its optimal dose, route, and underlying mechanisms.