Objective: To compare the potential beneficial effects of the angiotensin converting enzyme inhibitor (ACEI) benazepril and the angiotensin II receptor 1 blocker (ARB) irbesartan on vaginal vascular remodeling and fibrosis in female spontaneously hypertensive rats (SHRs).
Methods: Twelve-week-old female SHRs were treated with irbesartan or benazepril for 12 weeks. Vaginal renin angiotensin system (RAS) components were detected by polymerase chain reaction and western blot and vaginal α-smooth muscle actin (α-SMA), endothelial nitric oxide synthase (eNOS), and collagen III (Col III) were analyzed by western blot. Vaginal tissue sections were examined by hematoxylin and eosin staining, Masson trichrome staining, and immunohistochemical analysis of α-SMA and Col III.
Results: Irbesartan and benazepril had different impacts on vaginal RAS components. Both agents decreased vaginal α-SMA and Col III and increased eNOS expression in SHR. The wall/lumen thickness ratio of vaginal arterioles was similarly decreased following irbesartan and benazepril treatment. Both drugs also decreased collagen deposition in SHRs. There was no difference in vaginal vascular remodeling or fibrosis between the two groups.
Conclusions: Irbesartan and benazepril have different effects on vaginal RAS expression but similar positive effects against vaginal vascular remodeling and fibrosis.
Keywords: Hypertension; angiotensin II receptor 1 blocker; angiotensin converting enzyme inhibitor; benazepril; female sexual dysfunction; fibrosis; irbesartan; vascular remodeling.