[Function and structure of the vascular wall in experimental arterial hypertension. Effect of treatment]

The effects of converting enzyme inhibitor have been studied on the functions and structure of the arterial wall, and in both models of renovascular and spontaneously hypertensive rats. The arterial wall functions have been studied in terms of active vasomotricity, passive elasticity and transparietal convexion transport of proteins. Whatever the model used, hypertension was associated with significant changes in arterial wall functions: increase in smooth muscle cell tone, decrease in compliance, and decrease in transparietal filtration rate of proteins. These modifications could be reported to the increase in thickness of the media secondary to hypertrophy and hyperplasia of smooth muscle cell and to the increase in collagen network density. The effects of converting enzyme inhibitors on these phenomenons could depend on the experimental model used and the duration of treatment. In renovascular hypertensive animals, one month of treatment with perindopril normalized blood pressure and active compliance of the arterial wall. This functional benefit could be easily reported to the complete regression of the smooth muscle cell hypertrophy observed after treatment. By contrast, the increase in collagen network density was not regressed by treatment. By contrast, the increase in collagen network density was not regressed by treatment. By contrast, the increase in collagen network density was not regressed by treatment with trandolapril and thus the transparietal filtration rate of proteins remained decreased. In spontaneously hypertensive rats a perindopril treatment of long duration (3 months) partially regressed the functional change in compliance. This effect, once again, could be easily reported to the partial regression of medial hypertrophy which was associated, in this experimental condition, with a significant decrease in collagen network density.