Aortic Wall Remodeling in Rats with Nitric Oxide Deficiency Treated by Enalapril or Verapamil

Twenty mature male Wistar rats were maintained alive for 40 days, separated in four groups of five rats each: control, L-NAME (LN), L-NAME + Enalapril (LN + E), L-NAME + Verapamil (LN + V). Blood pressure (BP), left ventricular (LV) mass index, and aortic wall parameters were analyzed: aortic wall thickness, tunica media sectional area, surface density of lamellae (Sv[lamellae]), and smooth muscle cell nuclear profiles per section (SMC). At the end of the experiment, the LN group showed high BP and a high LV mass index (cardiac hypertrophy). The control group and the other groups showed significant differences in aortic wall thickness, tunica media sectional area, Sv[lamellae], and SMC. When comparing the LN group with both the LN + E group and the LN + V group, aortic thickness was not different. Tunica media sectional area and SMC differed between the LN group and the LN + E group. There were also differences between the LN group and the LN + V group in SMC. The Sv[lamellae] decreased in the following sequence: control group > LN group = LN + E group > LN + V group. In conclusion, treatment with enalapril and verapamil shows partial efficiency in preventing or treating aortic wall tunica media hypertrophy, suggesting that these alterations are due to a mechanism other than blood pressure control, where nitric oxide synthesis inhibition could be involved.