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Basic & Clinical Pharmacology &... Jan 2012Arterioles are the blood vessels in the arterial side of the vascular tree that are located proximal to the capillaries and, in conjunction with the terminal arteries,... (Review)
Review
Arterioles are the blood vessels in the arterial side of the vascular tree that are located proximal to the capillaries and, in conjunction with the terminal arteries, provide the majority of resistance to blood flow. Consequently, arterioles are important contributors to the regulation of mean arterial pressure and tissue perfusion. Their wall consists of cellular and extracellular components that have been traditionally classified as conforming three layers: an intima containing endothelial cells sited on a basement membrane; a media made of an internal elastic lamina apposed by one or two layers of smooth muscle; and an adventitia composed mostly of collagen bundles, nerve endings and some fibroblasts. These components of the arteriolar wall are dynamically interconnected, providing a level of plasticity to the arteriolar wall that blurs the traditional boundaries of a rigid layered classification. This MiniReview focuses on the structural conformation of the arteriolar wall and shows how wall components interact spatially, functionally and temporally to control vascular diameter, regulate blood flow and maintain vascular permeability.
Topics: Animals; Arterioles; Capillary Permeability; Connective Tissue; Connective Tissue Cells; Humans; Tunica Intima; Tunica Media; Vascular Resistance
PubMed: 21989114
DOI: 10.1111/j.1742-7843.2011.00813.x -
Hospital Practice (1995) Apr 2013Carotid artery intima-media thickness (IMT) is a biomarker for cardiovascular disease that also predicts the risk of cardiovascular mortality. Angiotensin-converting... (Review)
Review
Carotid artery intima-media thickness (IMT) is a biomarker for cardiovascular disease that also predicts the risk of cardiovascular mortality. Angiotensin-converting enzyme (ACE) inhibition is a unique therapeutic modality because it both treats hypertension and improves arterial health and cardiovascular disease outcomes. Controversy exists regarding the role of ACE inhibitors and angiotensin receptor blockers (ARBs) in IMT regression. Our article provides an update on how ACE inhibitors and ARBs could play a role in decreasing IMT.
Topics: Angiotensin Receptor Antagonists; Angiotensin-Converting Enzyme Inhibitors; Cardiovascular Diseases; Carotid Arteries; Humans; Renin-Angiotensin System; Risk Assessment; Tunica Intima
PubMed: 23680737
DOI: 10.3810/hp.2013.04.1026 -
Journal of the American College of... Jun 2009
Topics: Aorta, Abdominal; Arteriosclerosis; Carotid Arteries; Carotid Artery Diseases; Humans; Metabolic Syndrome; Tunica Intima; Ultrasonography
PubMed: 19520252
DOI: 10.1016/j.jacc.2009.03.029 -
PloS One 2020Aging causes stiffness and decreased function of the renal artery (RA). Histological study with light microscopy can reveal microscopic structural remodeling but no...
OBJECTIVES
Aging causes stiffness and decreased function of the renal artery (RA). Histological study with light microscopy can reveal microscopic structural remodeling but no functional changes. The present study aimed to clarify the association between structural and functional aging of the RA through the use of scanning acoustic microscopy.
METHODS
Formalin-fixed, paraffin-embedded cross-sections of renal arteries from 64 autopsy cases were examined. Speed-of-sound (SOS) values of three layers, which correspond to the stiffness, were compared among different age groups. SOS of the tunica media was examined in terms of blood pressure (BP) and SOS of the ascending aorta. Vulnerability to proteases was assessed by SOS reduction after collagenase treatment.
RESULTS
The tunica intima presented inward hypertrophy with luminal narrowing, and the tunica media showed outward hypertrophic remodeling with aging. SOS of the tunica media and internal and external elastic laminae showed a reverse correlation with age. SOS of the tunica media was negatively correlated with BP and strongly associated with that of the aorta. The tunica media of young RAs were more sensitive to collagenase compared with the old ones.
CONCLUSIONS
Scanning acoustic microscopy is useful for observing the aging process of the RA. This technique simultaneously shows structural and mechanical information from each portion of the RA. In the process of aging, the RA loses contractile function and elasticity as a result of protease digestion. The tunica media and the internal and external elastic laminae exhibit reduced stiffness, but the tunica intima stiffens with atherosclerosis. As a consequence, the RA's outer shape changes from round to oval with inward and outward hypertrophy. This indicates that the inner resistant intima supports the mechanical weakness of the tunica media to compensate for an increase in BP with aging.
Topics: Adult; Aged, 80 and over; Aging; Autopsy; Blood Pressure; Female; Humans; Male; Microscopy, Acoustic; Renal Artery; Tunica Intima; Tunica Media
PubMed: 33147291
DOI: 10.1371/journal.pone.0234759 -
Folia Morphologica 2019The aim of this study is to describe the morphology, morphometry and ultrastructure of segments of the thoracic and abdominal aorta portions in Chinchilla lanigera....
BACKGROUND
The aim of this study is to describe the morphology, morphometry and ultrastructure of segments of the thoracic and abdominal aorta portions in Chinchilla lanigera. Thickness measurements of the tunica intima and media complex of the aorta were taken.
MATERIALS AND METHODS
In all observed specimens, the thickness values for the tunica intima and media complex of the cranial thoracic aorta were significantly higher (mean: 702.19 μm) when compared to the values of other analysed aortic segments (means: 354.18 μm; 243.55 μm). Complex statistical methods were used to assess the differences between various aortic segments.
RESULTS AND CONCLUSIONS
The components of the vessel walls show variations in structure and thickness, presumably due to an adaptation to functional demand.
Topics: Animals; Aorta; Chinchilla; Tunica Intima; Tunica Media
PubMed: 30835342
DOI: 10.5603/FM.a2019.0023 -
American Journal of Hypertension Sep 2018Morphological and physiological changes in the vasculature have been described in the evolution and maintenance of hypertension. Hypertension-induced vascular... (Review)
Review
Morphological and physiological changes in the vasculature have been described in the evolution and maintenance of hypertension. Hypertension-induced vascular dysfunction may present itself as a contributing, or consequential factor, to vascular remodeling caused by chronically elevated systemic arterial blood pressure. Changes in all vessel layers, from the endothelium to the perivascular adipose tissue (PVAT), have been described. This mini-review focuses on the current knowledge of the structure and function of the vessel layers, specifically muscular arteries: intima, media, adventitia, PVAT, and the cell types harbored within each vessel layer. The contributions of each cell type to vessel homeostasis and pathophysiological development of hypertension will be highlighted.
Topics: Adipose Tissue; Animals; Arterial Pressure; Arteries; Humans; Hypertension; Tunica Intima; Tunica Media; Vascular Remodeling
PubMed: 29788246
DOI: 10.1093/ajh/hpy083 -
Gerontology 2014Arterial aging is a cornerstone of organismal aging. The central arterial wall structurally and functionally remodels under chronic proinflammatory stress over a... (Review)
Review
Arterial aging is a cornerstone of organismal aging. The central arterial wall structurally and functionally remodels under chronic proinflammatory stress over a lifetime. The low-grade proinflammation that accompanies advancing age causes arterial wall thickening and stiffening. These structural and functional alterations are consequences of adverse molecular and cellular events, e.g. an increase in local angiotensin II signaling that induces an inflammatory phenotypic shift of endothelial and smooth muscle cells. Thus, interventions to restrict proinflammatory signaling are a rational approach to delay or prevent age-associated adverse arterial remodeling.
Topics: Aging; Angiotensin II; Animals; Arteries; Atherosclerosis; Haplorhini; Humans; Hypertension; Myocytes, Smooth Muscle; Rabbits; Rats; Signal Transduction; Tunica Intima; Tunica Media; Vascular Remodeling
PubMed: 25171100
DOI: 10.1159/000362548 -
Brazilian Journal of Medical and... Jun 2009This review provides examples of the fact that different procedures for the measurement of atherosclerosis in mice may lead to interpretation of the extent of... (Review)
Review
This review provides examples of the fact that different procedures for the measurement of atherosclerosis in mice may lead to interpretation of the extent of atherosclerosis having markedly different biological and clinical significance for humans: 1) aortic cholesterol measurement is highly sensitive for the detection of early and advanced atherosclerosis lesions, but misses the identification of the location and complexity of these lesions that are so critical for humans; 2) the histological analysis of the aortic root lesions in simvastatin-treated and control mice reveals similar lesion morphology in spite of the remarkable simvastatin-induced reduction of the aortic cholesteryl ester content; 3) in histological analyses, chemical fixation and inclusion may extract the tissue fat and also shrink and distort tissue structures. Thus, the method may be less sensitive for the detection of slight differences among the experimental groups, unless a more suitable procedure employing physical fixation with histological sample freezing using optimal cutting temperature and liquid nitrogen is employed. Thus, when measuring experimental atherosclerosis in mice, investigators should be aware of several previously unreported pitfalls regarding the extent, location and complexity of the arterial lesion that may not be suitable for extrapolation to human pathology.
Topics: Animals; Anticholesteremic Agents; Aorta; Arteriosclerosis; Cholesterol; Disease Models, Animal; Humans; Mice; Simvastatin; Tunica Intima
PubMed: 19448893
DOI: 10.1590/s0100-879x2009000600001 -
Thorax 1994
Review
Topics: Humans; Hypertension, Pulmonary; Infant; Muscle, Smooth, Vascular; Pulmonary Artery; Tunica Intima
PubMed: 7974326
DOI: 10.1136/thx.49.suppl.s39 -
The Canadian Journal of Cardiology Feb 2006Cilostazol is a phosphodiesterase III inhibitor with pharmacological effects that include vasodilation, inhibition of platelet activation and aggregation, inhibition of... (Review)
Review
Cilostazol is a phosphodiesterase III inhibitor with pharmacological effects that include vasodilation, inhibition of platelet activation and aggregation, inhibition of thrombosis, increased blood flow to the limbs, improvement in serum lipids with lowering of triglycerides and elevation of high density lipoprotein cholesterol, and inhibition of vascular smooth muscle cell growth. Cilostazol has been shown in multiple randomized clinical trials to result in decreased claudication and improved ability to walk in patients with peripheral arterial disease. In addition, cilostazol has been shown in multiple randomized clinical trials to decrease restenosis in the setting of coronary stent implantation. The purpose of the present paper was to review the vascular effects of cilostazol and to present results of the major clinical trials of the use of cilostazol in peripheral arterial disease and percutaneous coronary intervention with stent implantation.
Topics: Animals; Cell Proliferation; Cilostazol; Coronary Restenosis; Endothelium, Vascular; Humans; Lipids; Peripheral Vascular Diseases; Phosphodiesterase Inhibitors; Platelet Aggregation Inhibitors; Tetrazoles; Tunica Intima
PubMed: 16498513
DOI: 10.1016/s0828-282x(06)70987-4