RESUMO
The in vitro anti-hypertrophic and hyperplastic actions of des-aspartate-angiotensin I (DAA-I) on cultured cardiovascular cells have been demonstrated in earlier experiments. The present study investigated its effects on the development of neointima in balloon catheter-injured carotid artery of the Sprague-Dawley (SD) rat and the development of cardiovascular hypertrophy in the spontaneously hypertensive rat. Treatment with i.v. DAA-I for 14 days post-injury dose-dependently attenuated the development of neointima. The maximum effect was obtained at 34 pmol/kg/day. The data support the possibility that endogenous angiotensins could inhibit neointima growth. This opens up avenues for their therapeutic elevation in combating neointima-related restenosis of which current drugs are not fully effective in suppressing. Five-week-old pre-hypertensive SHR, when orally administered with a dose of 769 nmol/kg/day DAA-I for a duration of 47 weeks, showed significant reduction in the development of cardiac and vascular hypertrophy compared to the untreated controls. Similar treatment with DAA-I had no effect on the Wistar Kyoto rats. The present findings support the contention that, besides angiotensin II, other endogenous angiotensins are also involved in the regulation and/or pathophysiology of the cardiovascular system.
