Role of the endothelium in the vasomotor effects of angiotensin I in isolated arteries with or without inhibition by MK 422.
We investigated in the isolated rabbit aorta the ability of the endothelium to attenuate the vasoconstrictor effects of angiotensin (ANG) I and II. After preincubation with enalaprilat, which inhibited the conversion of ANG I to ANG II by 80%, the contractile response to ANG I (10(-8) to 10(-6) mol/l) was significantly greater in aortae which were endothelium-denuded compared with endothelium-intact segments. There was no such difference for ANG II (10(-10) to 3 x 10(-8) mol/l). We conclude that an endothelium-mediated dilatation is part of the net vasomotor action of ANG I.
Lückhoff
A
A
Institute of Applied Physiology, University of Freiburg, Federal Republic of Germany.
Budek
W
W
Holtz
J
J
Busse
R
R
D000803:Angiotensin I / Q000494:pharmacology*; D000818:Animals; D001158:Arteries / Q000187:drug effects; D015773:Enalaprilat / Q000494:pharmacology*; D004730:Endothelium, Vascular / Q000502:physiology*; D005260:Female; D066298:In Vitro Techniques; D008297:Male; D009131:Muscle, Smooth, Vascular / Q000187:drug effects*; D011817:Rabbits
D000803:Angiotensin I; D015773:Enalaprilat