Kinins are peptide hormones that can exert a significant influence on the r
egulation of blood pressure and vascular tone due to their vasodilatatory,
natriuretic and growth modulating activity. Their cardiovascular involvemen
t in physiological and pathophysiological situations has been studied inten
sively since inhibitors for angiotensin I-converting enzyme and selective r
eceptor antagonists have become available for pharmacologically potentiatin
g or inhibiting kinin-mediated reactions. Molecular biological analysis and
the establishment of genetically modified animal models have also allowed
newer information to be acquired on this subject. In this review, the compo
nents and cardiovascularly relevant mechanisms of the kinin-kallikrein syst
em shall be described. Organ-specific effects concerning the kidneys, the v
ascular system, the heart and nervous tissue shall also be illustrated. On
this issue, the physiological functions and pathophysiological implications
of the kinin-kallikrein system should be clearly distinguished from the ma
ny, mostly endothelium-mediated protective effects which occur during ACE i
nhibition due to the potentiation of kinin effects. Finally, a view shall a
lso be cast upon newly discovered targets of action, which could be exploit
ed for therapeutically altering the kinin-kallikrein system.