Regression of experimental endometriotic implants in a rat model with the angiotensin II receptor blocker losartan.

Aim Endometriosis is a common disease in women of reproductive age, and many different treatments have been developed, although none has provided a cure. In this study, the efficacy of losartan, an angiotensin II type 1 receptor blocker and an antiangiogenic and anti-inflammatory agent, on regression of experimental endometriotic implants in a rat model was investigated. Methods Peritoneal endometriosis was surgically induced in 16 mature female Sprague- Dawley rats. The peritoneal endometriotic implant was confirmed after 28 days, and the animals were divided randomly into two groups. The control group ( n = 8) was given 4 mL/day tap water by oral gavage, and the losartan group ( n = 8) was given 20 mg/kg per day losartan p.o. We compared endometriotic implant size, extent and severity of adhesion, as well as plasma and peritoneal lavage fluid cytokine levels including vascular endothelial growth factor ( VEGF) and tumor necrosis factor ( TNF)-α, plasma inflammatory factor pentraxin-3 ( PTX-3) and C-reactive protein ( CRP) between the treatment groups. Results Mean surface endometriotic area, histological score of implants, adhesion formation, plasma VEGF, TNF, PTX-3 and CRP levels were significantly lower in the losartan group compared with control ( P < 0.05). Furthermore, the peritoneal VEGF level was lower in the losartan group than in the control group ( P < 0.001), but peritoneal TNF-α was similar in both groups ( P > 0.05). Conclusion Losartan suppressed the implant surface area of experimental endometriosis in rats and reduced the levels of plasma VEGF, TNF-α, PTX-3 and CRP. [ABSTRACT FROM AUTHOR]