Wall Of Muscular Arteries Research Articles

Propionibacterium acnes in granulomas of a patient with necrotising sarcoid granulomatosis

Necrotising sarcoid granulomatosis (NSG) was first described by Liebow1 in 1973. It is defined by three pathological features: the presence of a conglomerate mass of sarcoid-like granulomas; varying degrees of...

Apoptosis in the muscular arteries from young spontaneously hypertensive rats.

The purpose of this study was to test the hypothesis that a different incidence of apoptosis occurs in the mesenteric arteries of the spontaneously hypertensive rat (SHR) compared with its normotensive control the Wistar-Kyoto rat (WKY) at 1-2 weeks of age. We examined the incidence of apoptotic cells in the blood vessel wall of muscular arteries from the SHR and WKY at 1-2 weeks of age using two techniques of apoptosis measurement DNA laddering and 3'-OH end labelling. We also measured the volume of the blood vessel wall components and lumen sizes with the confocal microscope to determine whether a differential incidence of apoptosis occurred between the two rat strains. We used phenol/chloroform extraction to isolate genomic DNA and assess DNA fragmentation, with gel electrophoresis to determine DNA laddering, and 3'-OH end labelling, where the enzyme terminal deoxynucleotidyl transferase catalyses the addition of fluorescein-conjugated nucleotides to the cut ends of DNA, to detect in situ DNA fragmentation. The volume per unit length of the blood vessel structural components was measured by optical sectioning with the confocal microscope. We found that the SHR had a significantly decreased incidence of cellular apoptosis over WKY. This was true for both the electrophoretic method where SHR had significantly less fragmented DNA (molecular size < 600 bp) than WKY (P= 0.01), and for the microscopic method where SHR had fewer labelled cells in both the adventitia (P= 0.01) and the media (P= 0.0001) layers of large mesenteric arteries. The volumes of the adventitia, media and lumen in the large mesenteric arteries were similar between the two strains at this age. These findings suggest that a differential incidence of cellular apoptosis at the age of 1 -2 weeks may be responsible for the larger media volume found in older SHR and thus contributes to the development of hypertension in these animals.

Three‐Layer Appearance of the Arterial Wall in Intravascular Ultrasound Imaging:

A three‐layer appearance of the arterial wall in intravascular ultrasound imaging has been described, but its correspondence with a characteristic histologic structure is still controversial. Some studies emphasize the imprecision of vessel‐wall measurements carried out on the intravascular ultrasound image, while other studies cast doubt upon the reality of the three‐layer appearance and its correspondence with a characteristic histologic structure. The consequences of this disputed point are important with respect to the interpretation of such images. We performed an in vitro study using phantoms and heighty postnecroptic arteries to determine the relations existing between histology, acoustic properties of arterial wall tissue, and intravascular ultrasound image formation. Measurements carried out on phantoms showed a significant overestimation of wall thickness, equal to axial resolution and due to the radial impulse response of the imaging system. Measurements performed on normal arterial walls of muscular arteries with a three‐layer appearance or normal arterial walls of elastic arteries with a single‐layer appearance showed very clearly that there was no correlation with histologic measurements of the thickness of intima and media taken individually. However, measurements (n = 53), which include the intima plus the media, exhibit excellent correlation with histologic measurements: r = 0.95 ± 0.03, y = 1.02 + 11.2. The shiny internal ring of the muscular artery wall on the image corresponded always to the internal elastic lamina (IEL). Thus, the three‐layer appearance is not an artifact. However, specific alterations, which this appearance may undergo during image formation such as beam incidence angle, lateral and radial impulse responses, and the effects of proximity of the transducer to the arterial wall, modified the shape and sizes characterizing the IEL on intravascular ultrasound images. The description and understanding of such image alterations are necessary for both interpreting them and determining which are the only reliable measurements that can be performed.

The appearance of normal and abnormal arterial morphology on intravascular ultrasound

The ultrasonic appearance of in vitro normal and atherosclerotic arterial wall was investigated with an intravascular ultrasound (IVUS) probe. Fresh cadaver specimens were used: two carotid, two aorta, four iliac and eight superficial femoral arteries. The wall of muscular arteries has a three-layered sonographic appearance. The central hypoechoic layer corresponds to the media, which is primarily composed of smooth muscle. Elastic arteries whose media have a high elastin content appear uniformly echogenic. Calcified plaque is strongly echogenic with acoustic shadowing, fibrous plaque is moderately echogenic, and where there is no cellular matrix the plaque is poorly echogenic. IVUS can provide information about internal plaque architecture. Three-dimensional reconstructions can be generated using a transputer-based workstation coupled to the transducer, providing detailed views of surface contour.

Orientation of medial smooth muscle in the wall of systemic muscular arteries.

The study was undertaken to determine the pattern of alignment of muscle cells in the tunica media of muscular arteries. Brachial and femoral arteries from two small Rhesus monkeys and renal arteries from two rabbits were fixed under pressure with formalin, or glutaraldehyde followed by formalin. Sections were cut at 7 micron thickness at specific angles varying from zero to 30 degrees, and then stained with haematoxylin and eosin. The end coordinates of the medial muscle nuclei (appearing dark with the H & E stain) were recorded using a digitizer. Analysis was done as suggested by a previous modelling study by one of the authors; lengths of the individual nuclei as they appeared on the section were plotted as a function of the distance around the perimeter of the vessel. The distribution of lengths was consistent with a truly circumferential pattern of alignment for the muscle nuclei in the wall of muscular arteries. The standard deviation about the average circumferential pattern was +/- 13 degrees in the plane of the histological sections cut in cross section. The number density Nv of 4.4 x 10(5) mm-3 was higher than determined previously for human brain arteries and the nuclear length was 20% shorter (30 micron).

Radioautographic localization of hydralazine-1-C-14 in arterial walls.

SummaryBy radioautography, radiocarbon from hydralazine-1-C14 has been shown to be concentrated in the walls of muscular arteries in kidney, liver, spleen, heart, lung, brain, and muscle. It remains there in high concentrations for more than 2 days and in lower concentrations for more than 5 days.