On behalf of the organizing committee of this symposium, I would like to wel come you to Cologne and thank you very much for coming. We appreciate that some of the leading scientists in the field of hypertension have accepted our invi tation to participate actively at this conference. Our first symposium on renin-angiotensin, aldosterone, and hypertension took place at Titisee in the Black Forest in 1967. The second one, on the renin-angio tensin-aldosterone system under the influence of therapeutic procedures, was held at the same place in 1970. Five years later in 1975 at a third symposium...