Inhibition in vivo of the enzymatic inactivation of bradykinin and kallidin

A Modern Understanding of the Traditional and Nontraditional Biological Functions of Angiotensin-Converting Enzyme

“…The real breakthrough came with the substitution of a sulfhydryl group for the N-terminal carboxyl, giving rise to captopril with an IC 50 of 0.02 mM., an agent that, when orally administered to rats, inhibited the pressor effects of angiotensin I, augmented the actions of bradykinin, and "lower(ed) blood pressure in a model of renovascular hypertension" . It should be noted that sulfhydryl compounds had been found to inhibit ACE before the development of captopril; both Ferreira and Rocha e Silva (1962) and Erdoes and Wohler (1963) had used sulfhydryl compounds to potentiate bradykinin in the 1960s. Nonetheless, the development of captopril was a seminal event.…”

Cardiovascular and Gastrointestinal Effects of Bradykinin and Its Potentiation by Thiols in Rats

“…These investigations showed a consistant potentiation of the normal bradykinin effect (save one: 8-hydroxyquinoline) on those tissues and systems studied (11)(12)(13). It is noteworthy that the common property possessed by the aforementioned compounds is their ability t o complex divalent metals.…”

Proteolytic enzymes in clinical medicine

“…Open heart surgery is frequently attended by hemorrhagic complications. in one large study, a marked increase in plasminogen activator was demonstrated in 90 per cent of the cases. 115 Another group of defects might be described as chronic, in that they present with hematemesis, melena, or anemia rather than gross hemorrhage.…”