Aldosterone biosynthesis in kidney has been proved by means of kidney perfusion in vitro, high performance liquid chromatography, radioimmunoassay and TR-PCR, indicating that aldosterone biosynthesis is possible in tissues other than adrenal. Bilateral nephrectomy was carried out in male Wistar rats and the plasma renin activity would disappear after 30 hours. However, RT-PCR showed that the vasculature in the nephrectomized rats was still able to express renin mRNA. It means that the vasculature is different from the heart which depends on taking up renin from the circulation, while the vasculature takes renin produced locally in its own tissue to initiate the renin-angiotensin-aldosterone system. Perindopril, an angiotensin converting enzyme inhibitor (ACEI), inhibits not only the production of angiotensin II, but also the synthesis of aldosterone in the vasculature. ACEI reversion of vascular remodeling is probably related with its inhibition of aldosterone synthesis in the vasculature.