How it began
In 1939 the Brazilian pharmacologist Mauricio Rocha e Silva, working at the Instituto Biologico in Sao Paulo, began a study of circulatory shock and of enzymes involved in the effects of snake bites. In 1948 he and his colleagues Wilson Teixeira Beraldo and Gastao Rosenfeld were examining the blood plasma of animals injected with venom from the Brazilian lancehead, Bothrops jararaca. In that plasma they found a new peptide, which they called bradykinin.
How it works
Bradykinin is a peptide made of nine amino acids. The name comes from Greek words for slow and to move, because intestinal smooth muscle exposed to it contracted slowly. The Brazilian group also found that bradykinin makes blood vessels widen, which lowers blood pressure. It is described in the pharmacology literature as a powerful hypotensive and smooth muscle stimulating polypeptide.
What lasted
Sergio Ferreira of the University of Sao Paulo later found another substance in the same venom that strongly increased both the length and the size of bradykinin's effect on blood vessels and blood pressure. Study of the venom peptides showed that one of them, teprotide, lowered blood pressure with a lasting effect. That work was the starting point for the design of captopril, a drug for high blood pressure.
Where it stands today
Rocha e Silva is remembered in the pharmacology literature as the discoverer of bradykinin. He held a chair of pharmacology and died in Sao Paulo in December 1983 at the age of 73. A historical paper links his work on snake venom and bradykinin to the rise of pharmacology as a research field in Brazil. Captopril, which grew from the venom studies, is taught as a standard case of drug design.
