Vasa vasorum forms a network of microvessels within and around the walls of large blood vessels and is thought to be necessary to deliver oxygenated blood to the outer parts of the vessel wall that are inadequately nourished by diffusion from luminal blood. Vasa vasorum flow, therefore, may play an important role for aortic wall structure and function. Angiotensin II and bradykinin are two important vasoactive peptides, which produce vasoconstriction and vasodilatation, respectively. They can also change the permeability of microcirculation. In the present study, we documented the effect of different concentrations of ANG II and bradykinin on the vasa vasorum of isolated rabbit throcic aorta in vitro. Using a camera system, we observed changes in the number of leakages and diameter of vasa vasorum in response to perfusion of ANG II and BK, their antagonists (AT 2 receptor antagonist PD 123319, AT1 receptor antagonist EXP3174, B2 receptor antagonist HOE 140, B1 receptor antagonist (Leu9 ) Des Arg 10- KD (1 ?M), and nitric oxide synthase inhibitor L-NAME."--Résumé abrégé par UM
