Blood pressure produces deleterious effects in genital structures of female spontanously hypertensive rat

Abstract

Emerging knowledge from clinical and experimental studies provides a new insight for understanding the pathophysiology of female sexual dysfunction in patients with arterial hypertension. The aim of the present study was to evaluate possible morphological alteration in clitoris and vagina from spontaneous hypertensive rats (SHR) and compared with normotensive Wistar-Kyoto (WKY) rats. Twelve-week-old female SHR and WKY rats, were studied during six months. G1 Control WKY (n = 10) and G2 SHR (n = 10). Systolic blood pressure (SBP) was recorded monthly. At end of the experiment, clitoris and vagina were dissected out and processed by Masson's trichrome, monoclonal anti-a-smooth-muscle actin, anti- collagen type I and type III, and anti TGFb1. Histomorphometric evaluation revealed that SHR presented higher amount of clitoral cavernous smooth muscle (20 ± 6.9 % versus 7 ± 4.4 %; p< 0.01), as well as vascular smooth muscle (16.1 ± 3.6 % versus 9 ± 2 %; p< 0.01); higher TGFb1 in clitoral vessel wall (2.7 ± 1.4 % versus 1.4 ± 0.5 %; p< 0.01); higher wall/lumen ratio (p< 0.01) in both vaginal and clitoral vessels; and remarkable interstitial fibrosis (60.7 ± 4.9 % versus 38.6 ± 2.7 %; p< 0.01), expressed by a higher amount in interstitial collagen type III and I (p< 0.01) in both clitoris and vagina, when compared to WKY rats. In addition, nerve fibers from clitoral and vaginal tissue in SHR showed a notable fibrosis at perineurium and endoneurium. SHR showed positive correlation between SBP and clitoral cavernous smooth muscle (r= 0.87 p< 0.01); SBP and fibrosis in clitoris (r= 0.81 p< 0.01); and SBP and collagen type I and III (r= 0.92 p< 0.01; r= 0.84 p< 0.01) in clitoris respectively: Similar findings were observed between SBP and collagen type I and III in vagina (r= 0.68 p< 0.05; r= 0.75 p< 0.05). According to these results we conclude that SHR present morphologic changes in clitoral vessels as well as in clitoral cavernous space, which have a high positive correlation with the high blood pressure level. Moreover, the increase in extracellular matrix expansion affects not only the clitoral and vaginal interstitium but also the nerve structures from both clitoris and vagina.