The relationship between renin, angiotensin, and aldosterone is one of the most intriguing observations made within the last few years. The story of these three compounds began with the discovery of renin. In 1898 Tigerstedt and Bergman, of Stockholm, demonstrated the presence of renin in the kidney. They showed that the infusion of extracts of rabbits' kidneys caused a rise in blood pressure. The pressor substance was a protein with enzymatic properties. It was renin. In a modest way these investigators pointed out that they wanted simply to draw attention to the possible importance of the blood-pressure-raising substance formed in the kidney.
Renin remained dormant for 36 years until Goldblatt and his group in Cleveland demonstrated experimental renal hypertension by clamping the renal artery. This discovery produced a chain reaction in hypertensive research which is still in effect. What caused the rise in blood pressure in Goldblatt's experiment? Houssay and