Synergistic effect of angiotensin-(1-7) on bradykinin arteriolar dilation in vivo.
The interaction between angiotensin [Ang-(1-7)] and bradykinin (BK) was determined in the mesentery of anesthetized Wistar rats using intravital microscopy. Topical application of BK and Ang-(1-7) induced vasodilation that was abolished by the BK B2 receptor antagonist HOE-140 and the Ang-(1-7) antagonist A-779, respectively. BK (1 pmol)-induced vasodilation, but not SNP and ACh responses, was potentiated by Ang-(1-7) 10 pmol and 100 pmols. The effect of 100 pmol of Ang-(1-7) on BK-induced vasodilation was abolished by A-779, indomethacin, and L-nitroarginine methyl esther, whereas losartan was without effect. Enalaprilat treatment enhanced the BK- and Ang-(1-7)-induced vasodilation and the potentiating effect of Ang-(1-7) on BK vasodilation. The potentiation of BK-induced vasodilation by Ang-(1-7) is a receptor-mediated phenomenon dependent on cyclooxygenase-related products and NO release.
Oliveira
M A
MA
Department of Pharmacology, Institute of Biomedical Sciences, University of São Paulo, Brazil.
Fortes
Z B
ZB
Santos
R A
RA
Kosla
M C
MC
De Carvalho
M H
MH
D000803:Angiotensin I; D000804:Angiotensin II / Q000031:analogs & derivatives / Q000378:metabolism / Q000494:pharmacology*; D000806:Angiotensin-Converting Enzyme Inhibitors / Q000494:pharmacology; D000818:Animals; D001160:Arterioles / Q000187:drug effects / Q000502:physiology; D001920:Bradykinin / Q000031:analogs & derivatives / Q000378:metabolism / Q000494:pharmacology*; D065168:Bradykinin Receptor Antagonists; D004357:Drug Synergism; D015773:Enalaprilat / Q000494:pharmacology; D008638:Mesenteric Arteries / Q000187:drug effects; D009569:Nitric Oxide / Q000378:metabolism; D010446:Peptide Fragments / Q000378:metabolism / Q000494:pharmacology*; D011453:Prostaglandins / Q000378:metabolism; D051381:Rats; D017208:Rats, Wistar; D043782:Receptor, Bradykinin B2; D014664:Vasodilation / Q000187:drug effects; D014665:Vasodilator Agents / Q000378:metabolism / Q000494:pharmacology*
C092006:7-Ala-angiotensin (1-7); D000806:Angiotensin-Converting Enzyme Inhibitors; D065168:Bradykinin Receptor Antagonists; D010446:Peptide Fragments; D011453:Prostaglandins; D043782:Receptor, Bradykinin B2; D014665:Vasodilator Agents; D000804:Angiotensin II; D009569:Nitric Oxide; C065679:icatibant; D000803:Angiotensin I; D015773:Enalaprilat; C118790:angiotensin I (1-7); D001920:Bradykinin