Kininase-independent potentiation of endothelium-dependent relaxations to kinins by converting enzyme inhibitor perindoprilat.
Abstract
AIM: The present study examined whether or not the resistance to degradation of
bradykinin analogs affects the kinin-potentiating action of the inhibitor of
converting enzyme, perindoprilat.
METHODS: Hydrolysis of Hyp3,Tyr(Me)8 -bradykinin by ACE present in isolated
canine coronary arteries was assessed by determination of peptide metabolites
using electrospray mass spectrometry, and compared to that of bradykinin.
Contractions and relaxations of isolated rings of coronary arteries, with and
without endothelium, were recorded as changes in isometric force.
RESULTS: After a 30 min incubation, most of the bradykinin was degraded by the
arteries, while less than 10 % of Hyp3,Tyr(Me)8 -bradykinin was hydrolysed. In
organ chambers, Hyp3,Tyr(Me)8 -bradykinin like bradykinin caused relaxations of
isolated canine coronary arteries with endothelium that could be attributed to
both NO and endothelium-derived hyperpolarizing factor (EDHF). Perindoprilat
caused a comparable leftward shift in the concentration-relaxation curves for
bradykinin and Hyp3,Tyr(Me)8 -bradykinin.
CONCLUSION: Impairment of the degradation of bradykinin is not an essential
mechanism by which perindoprilat potentiates the actions of kinins.
Keywords:
bradykinin analogs affects the kinin-potentiating action of the inhibitor of
converting enzyme, perindoprilat.
METHODS: Hydrolysis of Hyp3,Tyr(Me)8 -bradykinin by ACE present in isolated
canine coronary arteries was assessed by determination of peptide metabolites
using electrospray mass spectrometry, and compared to that of bradykinin.
Contractions and relaxations of isolated rings of coronary arteries, with and
without endothelium, were recorded as changes in isometric force.
RESULTS: After a 30 min incubation, most of the bradykinin was degraded by the
arteries, while less than 10 % of Hyp3,Tyr(Me)8 -bradykinin was hydrolysed. In
organ chambers, Hyp3,Tyr(Me)8 -bradykinin like bradykinin caused relaxations of
isolated canine coronary arteries with endothelium that could be attributed to
both NO and endothelium-derived hyperpolarizing factor (EDHF). Perindoprilat
caused a comparable leftward shift in the concentration-relaxation curves for
bradykinin and Hyp3,Tyr(Me)8 -bradykinin.
CONCLUSION: Impairment of the degradation of bradykinin is not an essential
mechanism by which perindoprilat potentiates the actions of kinins.