Inhibitory effect of insulin on bradykinin-induced venodilation.
BACKGROUND
Excessive insulin is one of the risk factors of hypertension and arteriosclerosis despite its vasodilative properties shown in recent studies. Although many vasoactive substances contribute and interact with each other in the development of hypertension, the interactions between insulin and other vasoactive substances have yet to be elucidated.


OBJECTIVE
To assess the effect of insulin on the action of bradykinin.


METHODS
The vasodilating effect of bradykinin was evaluated, with or without coadministration of insulin, in human dorsal hand veins of healthy volunteers. In cultured porcine aortic endothelial cells, the bradykinin-induced increase of intracellular calcium was also investigated before and after insulin administration.


RESULTS
Insulin significantly attenuated bradykinin-induced increase in intracellular calcium and venodilation in cultured endothelial cells and human dorsal hand veins, respectively.


CONCLUSIONS
These findings suggest that insulin attenuates the bradykinin-induced calcium elevation in endothelial cells and may decrease the production of vasodilative substances from endothelial cells, resulting in the reduction of vasodilation. This effect may contribute to the development of hypertension in patients with hyperinsulinaemia.
Kimura
M
M
Department of Clinical Pharmacology, Hamamatsu University School of Medicine, Japan.
Watanabe
H
H
Takahashi
R
R
Kosuge
K
K
Umemura
K
K
Hayashi
H
H
Ohashi
K
K
Ohno
R
R
D000328:Adult; D000818:Animals; D001011:Aorta / Q000166:cytology / Q000187:drug effects / Q000378:metabolism; D001920:Bradykinin / Q000494:pharmacology*; D002118:Calcium / Q000378:metabolism; D002478:Cells, Cultured; D003600:Cytosol / Q000378:metabolism; D004730:Endothelium, Vascular / Q000166:cytology / Q000187:drug effects / Q000378:metabolism; D006225:Hand / Q000098:blood supply; D006801:Humans; D007328:Insulin / Q000494:pharmacology*; D008297:Male; D009994:Osmolar Concentration; D012016:Reference Values; D013552:Swine; D014664:Vasodilation / Q000187:drug effects*; D014680:Veins / Q000187:drug effects* / Q000502:physiology
D007328:Insulin; D001920:Bradykinin; D002118:Calcium