Effects of repeated propranolol administration in a rat model of surgically induced endometriosis

OBJECTIVES: To determine whether propranolol has an inhibitory effect on the angiogenesis of endometriosis in an experimental rat model or not. STUDY DESIGN: This was an experimental animal model study. Twenty-four female Wistar albino rats (200-250 g) were used to create a model for surgical induction of endometriosis. Two rats died during the surgeries. The rats were randomly divided into treatment (n=11) and control groups (n=10), which were treated with daily intraperitoneal propranolol (10 mg/kg) and saline (2 mL), respectively. Study duration was 8 weeks. The volumes and histopathological findings of the implants, and immunochemistry for vascular endothelial growth factor (VEGF), metalloproteinase (MMP)-2, and MMP-9 were evaluated. RESULTS: Viable endometriotic implants were created in all animals. In the propranolol-treated group, the mean implant volume significantly decreased after treatment (142.5 vs. 32.1 mm(3), respectively; p=0.008), while the mean implant volume significantly increased in the control group (141.0 vs. 174.2 mm(3), respectively; p=0.009). There were also significant reductions in VEGF immunoreactivity scores and both stroma and epithelium MMP-2 and MMP-9 immunoreactivity scores in the propranolol-treated group compared with the control group (p<0.005 for all scores). CONCLUSIONS: Propranolol may suppress endometrial tissue by its antiangiogenic activity through inhibitory actions on VEGF, MMP-2, and MMP-9. Therefore, propranolol is a promising candidate drug for effective treatment of patients with endometriosis, which needs to be confirmed with further studies.