20 research outputs found
MEDIAL NECROSIS AND ACUTE ALTERATIONS IN AORTIC DISTENSIBILITY FOLLOWING REMOVAL OF THE VASA VASORUM OF CANINE ASCENDING AORTA
Objective: It is known that the outer layers of the thoracic aorta
receive substantial blood flow through vasa vasorum. This study was
undertaken to test the hypothesis that removal of vasa vasorum flow will
alter the elastic properties of the ascending aorta. Methods:
Distensibility of the ascending aorta was determined before and 30 min
after careful removal of the periaortic fat network which contains the
vasa vasorum in 10 acutely instrumented dogs (experimental group) and
the results were compared with those obtained from six weight matched
sham operated control dogs. Aortic distensibility was measured using the
formula: distensibility=2xpulsatile changes in aortic diameter
divided-by (diastolic aortic diameterXpulse pressure). Aortic pressures
were measured directly from the ascending aorta by a pressure gauge.
Aortic diameters were simultaneously determined by an elastic air filled
ring connected to a transducer. The efficacy of the technique for the
interruption of vasa vasorum blood supply to the aortic wall was proved
in six additional animals by histology of transverse blocks of aortic
wall from the area of interest. Histology was performed before vasa
vasorum removal in two animals, 30 min after vasa vasorum removal in
another two, and 15 d after vasa vasorum removal in the remainder.
Results: At baseline, there was no difference in the measured variables
between the two groups. Aortic distensibility decreased significantly in
the experimental group after vasa vasorum removal by 0.90(SEM 0.17)
10(-6).cm2-dyn-1 (p<0.001), while it remained unchanged in the control
group during the experiment. Complete removal of vasa vasorum of the
ascending aorta was found in experimental group animals which were
killed 30 min after operation, while ischaemic medial necrosis was
observed in those killed 15 d after operation. Conclusions: Vasa vasorum
removal led to an acute decrease in the distensibility of the ascending
aorta. Lack of blood supply to the outer part of the aortic wall is most
likely to have accounted for these findings
Determining the Prognostic Implications of Erectile Dysfunction for Future Cardiovascular Disease with Noninvasive Testing
Penile microvascular endothelial function in hypertensive patients: effects of acute type 5 phosphodiesterase inhibition
Cocoa, blood pressure, and vascular function
The consumption of a high amount of fruits and vegetables was found to be associated with a lower risk of coronary heart disease and stroke. Epidemiologically, a similar relationship has been found with cocoa, a naturally polyphenol-rich food. Obviously, double blind randomized studies are difficult to perform with cocoa and chocolate, respectively. However, intervention studies strongly suggest that cocoa has several beneficial effects on cardiovascular health, including the lowering of blood pressure, the improvement of vascular function and glucose metabolism, and the reduction of platelet aggregation and adhesion. Several potential mechanisms through which cocoa might exert its positive effects have been proposed, among them activation of nitric oxide synthase, increased bioavailability of nitric oxide as well as antioxidant, and anti-inflammatory properties. It is the aim of this review to summarize the findings of cocoa and chocolate on blood pressure and vascular function