The effect of different antihypertensive drugs on cavernous tissue in experimental chronic renal insufficiency

Male erectile dysfunction increases in prevalence in patients with severe chronic renal failure. Since arterial hypertension induces significant damage in cavernous tissue (CT), and considering that hypertension is extremely common in patients with end-stage renal disease (ESRD), the aim of this study was to evaluate the effect of the most conventionally employed antihypertensive drugs on CT in a rat model of renal insufficiency.

Five groups of male rats with subtotal nephrectomy (STNx) and 1 with sham operations were studied over 6 months: STNx without treatment, STNx with benazepril (BZ), STNx with losartan (LS), STNx with amlodipine (AML) and STNx with atenolol (AT) plus the sham group. All rats were sacrificed at 6 months after STNx, and penises processed for LM and immunohistochemical studies. Cavernous smooth muscle (CSM) and vascular smooth muscle (VSM) from cavernous arteries and the amount of collagen type III were evaluated.

All groups with antihypertensive drugs showed similar control in blood pressure throughout the study. Un-treated STNx, STNx with AML and STNx with AT presented significant (p<0.01) hypertrophy in both VSM and CSM, together with an increased amount of collagen type III in CT. Conversely, STNx with either BZ or LS showed a substantial (p<0.01) reduction in all of these variables, with values not different from the sham group. There was a significant (p<0.01) negative correlation between creatinine clearance and the amount of VSM, CSM and collagen type III deposition in CT in untreated STNx, STNx with AML and STNx with AT, but not in STNx with BZ, STNx with LS and sham.

These results suggest that the interactions against the renin-angiotensin system (RAS) either by ACE inhibitors or angiotensin AT1 receptor blockers produce considerable benefits regarding structural abnormalities in CT in this animal model of renal insufficiency beyond blood pressure control.