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

To determine whether propranolol has an inhibitory effect on the angiogenesis of endometriosis in an experimental rat model or not.

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.

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).

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.