Info

SMCs transformation from a contractile to a synthetic proliferative phe-notype is, in part, modulated by integrin a5p1 69 . Interestingly, integrins a1p1, a2p1, and a are upregulated during the phenotypic transformation 70-72 . As mentioned before, contact with the surrounding collagen matrix may control ECM production in phenotypically modified SMCs. In this regard, cell adhesion studies in SMCs indicate that the a1p1 and a2p1 integrins may be the dominant receptors for triple helical domains...

Atherosclerosis Arterial Stiffness and Antihypertensive Therapy

As shown earlier in this book, the links between atherosclerosis, arterial stiffness, age and high BP are often difficult to establish, particularly according to age. Many atherosclerotic alterations (AA) are subclinical and difficult to define in routine clinical investigations. On the other hand, many markers have been proposed, such as defects in vascular relaxation, alterations in endotheli-um-dependent flow dilatation and or presence of atherosclerotic plaques (see chapter by Baldewsing et...

Mechanical Stress and Arterial Remodeling

An arterial wall is a complex tissue composed of different cell populations capable of structural and functional changes, in response to direct injury and atherogenic factors, or to modifications of long-term hemodynamic conditions. The principal geometric modifications induced by hemodynamic alterations are changes of arterial lumen and or arterial wall thickness due to activation, proliferation and migration of VSM cells, and rearrangements of cellular elements and ECM 12-18 . The mechanical...

Amplification and Reflection Central vs Peripheral BP

The morphology of a pulse contour at any point along the vascular tree represents the sum of the forward and reflected pressure waves at that point. Pulse wave morphology is unique in each artery because of differences in time of arrival of the forward and reflected pressure waves. Unlike diastolic or mean BP, systolic BP is thus not constant throughout the arterial tree. In the arm, the amplitude of the forward wave is generally much greater than the amplitude of the reflected wave, so...

Relationship between Atherosclerosis and Hyperhomocysteinemia

Homocysteine is a sulfur-containing amino acid, which in humans can only be derived from the demethylation of the essential amino acid methio-nine. S-adenosylmethionine and S-adenosylhomocysteine are intermediates in this important biochemical pathway, called transmethylation, in which S-adenosylmethionine donates its methyl group to a variety of acceptors, such as guanidinoacetic acid, phosphatidylethanolamine, norepinephrine, DNA, RNA and protein amino acid residues. This reaction is driven...

Carotid Atherosclerosis Arterial Stiffness and Stroke Events

Enrico Agabiti-Rosei Maria Lorenza Muiesan Internal Medicine, Department of Medical and Surgical Sciences, University of Brescia, Brescia, Italy Assessment of intima-media thickness or of measures of large arteries compliance may identify patients at increased risk for stroke. In fact, carotid atherosclerosis and arterial stiffness are both related to risk factors associated with the occurrence of stroke. In addition, several cross-sectional studies have shown that risk factors associated with...

Abstract

It is well known that dyslipidemia and hypertension frequently coexist. There is increasing recognition of a mutually facilitative interaction between dyslipidemia and re-nin-angiotensin system RAS activation in the development of atherosclerosis. Both of these systems share many of the same properties in terms of activation of pro-inflammatory, pro-oxidant and pro-atherosclerosis pathways. Statins in particular have been shown to influence the biology of endothelial cells, vascular smooth...

Effects of Statins on Vascular Elasticity

Determinant of Vascular Elasticity and Compliance Vascular elasticity or compliance or stiffness is a major determinant of vascular resistance. The elasticity is determined by all components of the vessel wall, including the endothelium, SMCs, and the interstitium composed primarily of fibroblasts. Table 2. Evidence for blood pressure-lowering effect of statins Table 2. Evidence for blood pressure-lowering effect of statins Fluvastatin lowered blood pressure by 8-16 mm Hg Patients with...

Statins and Blood Pressure

Interaction of Dyslipidemia and Renin-Angiotensin System RAS Interactions between dyslipidemia and activation of neurohumoral systems, such as RAS, may not only explain the frequent coexistence of hypertension and dyslipidemia, but also play an important role in the pathogenesis of atherosclerosis. Experimental data suggest that the effects of Ang II and lipo-proteins on atherogenic risk are not independent and that the pathways by which Ang II and dyslipidemia lead to vascular disease may...

Pulse Transmission in Conduit Arteries

There has been a long tradition of assuming that changes in brachial cuff BP are similar to those at the heart or in peripheral target organs. As discussed, this is simply not the case due to intra- and interindividual differences in forward wave transmission and wave reflection 45, 46 . Differences in systolic BP from one site to another can be traced to alterations in the timing and amplitude of the forward and reflected pressure waves fig. 3 . Unlike diastolic or mean BP, systolic BP is thus...

Does Brachial Pulse Pressure Predict Coronary Events

Unita di Ricerca Cl nica, Cardiolog a Preventiva, Struttura Complessa di Cardiolog a, Ospedale R. Silvestrini, Perugia, Italy Brachial pulse pressure PP is an established risk marker for cardiovascular disease. PP is largely determined by the stroke volume in young subjects, although the progressive amplification of pulse wave from central to peripheral arteries could make brachial PP not representative of the central PP in the young. With advancing age, brachial PP better reflects the...

Arterial Wall Structure Function Relations

Changes in the structure and function of the aorta and to a lesser extent the central arteries are the principal features underlying changes in PP. Large 'elastic arteries' are composed of three layers the intima, the tunica media, and the adventitia 23 , In the proximal thoracic aorta, elastic lamellae are normally attached to smooth muscle cells to form 'contractile-elastic units' 24 that damp pulsation. Collagen is found in the adventitia and media, while elastin is located in the tunica...