Bradykinin Analogs

Abstract Kinins, like bradykinin, are small polypeptides (MW, 1-2.5 kDa). Some are released from mammalian tissues during pathogenic disorders such as anaphylactic and hemorrhagic shock, arthritis, burns, liver cancer and cirrhosis, inflam mation, migraine, pancreatitis, etc. (3). Although in the mammalian CNS the function and mode of action of bra dykinin, or related kinins, is still obscure, bradykinin is con sidered to be a brain peptide (11). Moreover, studies on the role of kinins in the mammalian brain have demonstrated that these peptides significantly affect various aspects of be havior (1,14). Wasp kinin, a bradykinin-like substance, is the first of several similar agents to have been isolated from the venom of social wasps (12,17). Threonine6-bradykinin (Thr6-BK) is present in the venom of a solitary wasp (15). Intragan glionic perfusion of insect ganglia with kinins induces a de layed and irreversible block of synaptic transmission (9,10), an effective mechanism to render the wasp’s prey immobile. Cyclic bradykinins also possess specific kininergic (bradykinin-like) activity in mammalian tissues.