Bradykinin is a nonapeptide that is mainly found in animal preparations that are treated with the venom of the snake, Bothrops jararaca1,2. It dialates blood vessels that in turn leads to decrease in blood pressure2. Bradykinin analogs are slightly modified structural derivatives of bradykinin that perform similar functions as bradykinin3.

Bradykinin was discovered in the blood plasma of animals that were treated with the venom from the Brazilian snake, Bothrops jararaca1,2. The discovery was part of a study that was related to toxicology of snake bites. Bradykinin analogs were synthesized by solid-phase techniques in 1975 and their function was studied in rats and rabbits3.