Thoracic Aorta Artery Research Articles

Effect and mechanism of ubiquitin-like protein FAT10 on AngⅡ induced endothelial cell inflammation

Objective: To investigate the role and related mechanism of ubiquitin-like protein FAT10 in the angiotensin Ⅱ (AngⅡ)-induced endothelial cell inflammatory responses. Methods: The Western blot was used to detect the protein expression of FAT10 in 16-weeks old WKY rat carotid artery, thoracic aorta artery, renal artery and vascular smooth muscle cells (VSMC), human umbilical vein endothelial cells (HUVEC) and human breast cancer cells (MDA-MB-231). The optimal concentration and stimulation time of AngⅡ on inducing the highest FAT10 in HUVEC were determined. The following plasmids were constructed: control plasmid, overexpression FAT10 plasmid (Flag-FAT10), invalid interference plasmid, and interference FAT10 plasmid (sh-FAT10). These plasmids were then transfected into HUVEC cells and divided into following groups: control group, Flag-FAT10 group, invalid interference group, and sh-FAT10 group. After culturing with 100 nmol/L AngⅡ for 36 h, the control group and the Flag-FAT10 group were treated with reactive oxygen species scavenger N-acetyl-L-cysteine ​​(NAC), the protein expression levels of the inflammatory factor monocyte chemotactic protein-1 (MCP-1) and tumor necrosis factor-α (TNF-α) were measured. Laser confocal microscopy was used to detect the generation levels of reactive oxygen species in the cells of vrious groups. Results: FAT10 was expressed in carotid artery, thoracic aorta, and renal artery of normal blood pressure rats and expressed in HUVEC, VSMC, MDA-MB-231. The expression level of FAT10 gradually increased in proportion to the increase of the time and concentration of AngⅡ stimulation in HUVEC, and the expression level of FAT10 was the highest when the HUVEC was treated with 100 nmol/L AngⅡ for 36 h (P<0.01). The protein expression level of MCP-1 (P<0.001) and TNF-α (P<0.01) was higher in AngⅡ treated HUVEC with FAT10 overexpression, while the expression level of MCP-1 and TNF-α protein was lower in AngⅡ treated HUVEC with FAT10 knockdown (all P<0.01). The level of intracellular reactive oxygen species (ROS) production was significantly increased with FAT10 overexpression (P<0.001), and the level of ROS was decreased when the expression of FAT10 was interfered (P<0.05). The increased level of MCP-1 and TNF-α proteins in FAT10 overexpressed HUVEC was reversed by NAC (all P<0.05). Conclusion: FAT10 promotes the release of inflammatory factors induced by AngⅡ in endothelial cells by increasing the level of intracellular ROS production.

Chronic red laser treatment induces hypotensive effect in two-kidney one-clip model of renovascular hypertension in rat.

To evaluate whether the chronic effect of photobiomodulation therapy (PBM) onsystolic arterial pressure (SAP)from two kidneys one clip (2K-1C) hypertension animal models can cause a hypotensive effect. Serum levels of nitric oxide were also analyzed and the assessment of lipid peroxidation of the thoracic aorta artery. Male Wistar rats were used. Hypertensive animals (2K-1C) with Systolic arterial pressure (SAP) greater than or equal to 160mmHg were used. Systolic arterial pressure (SAP) was determined by the tail plethysmography technique. Normotensive (2K) and hypertensive (2K-1C) rats were treated to PBM for 4weeks using a laser whose irradiation parameters were: red wavelength (λ) = 660nm: operating continuously; 56s per point (3 points) spot size = 0.0295 cm2; average optical power of 100 mW; energy of 5.6J per point; irradiance of 3.40 W/cm2; fluency of 190J/cm2 per point. The application was on the animals tails, at 3 different points simultaneously, in contact with the skin. To assess serum nitrite and nitrate (NOx) levels, blood collection was performed after chronic PBM treatment, 24h after the last laser application. The evaluation of the lipid peroxidation of the thoracic aorta artery was performed by measuring the concentration of hydroperoxide by the FOX method. Chronic photobiomodulation therapy (PBM) by red laser (660nm) can induce a hypotensive effect in 64% of 2K-1C hypertensive animals, which we say responsive animals. There was no difference in serum NO levels 24h after the last red laser application, between treated and non-treated groups. Aortic rings from 2K-1C hypertensive animals present a higher lipid peroxidation. The chronic PBM treatment by red laser decreased aortic rings lipid peroxidation in hypertensive responsive groups, compared to control. our results indicate that chronic PBM made by red laser has an important hypotensive effect in renovascular hypertensivemodels, by a mechanism that involves decrease in oxidative stress from vascular beds.

Functional and morphological study of the effects of carvacrol on smooth muscle of the thoracic aorta in the rat.

The leaves of Origanum are widely used in herbal medicine hence of having many beneficial ingredients, one of these important compounds is Carvacrol. The inhibitory effect of Carvacrol was the core of this study by applying different kinds of stimulants to smooth muscles in the wall of thoracic aorta in rats. To investigate the pharmacological effects of Carvacrol, the main active ingredient present in the medicinal plant Origanum, on the contractile activity and morphology of the smooth muscle of the rat thoracic aorta. After the thoracic aorta arteries were isolated and prepared for the experiments, each thoracic aorta was cut into 5-mm ring segments; different stimulants were used (Potassium Chloride, Norepinephrine, U46619, and α,β-methylene ATP) in the presence and absence of Carvacrol on four groups of rats. The isolated rings were placed and connected to a force transducer which in turn linked to a data acquisition system via an amplifier to record the effect of each stimulant. GraphPad Prism version 5.02 for Windows, one-way analysis of variance followed by Dunnett's multiple comparison test. It was found out that Carvacrol obstructs the contractile responses elicited by exogenous NA, KCl, U46619, and α,β-methylene ATP in a concentration dependent manner. The addition of Carvacrol in the experimental rats showed an increase in the thickness of tunica media as evident by the number of smooth muscle layers and laminae of elastic fibers. It was found that Carvacrol reduced the vascular smooth muscle contractility in the rat thoracic aorta. The mechanism of action is presumed to be achieved through interfering with the mobilization of both intracellular and extracellular Ca2+ through different receptors. Furthermore, it might be suggested that Carvacrol in high doses stimulates smooth muscles in the wall of aorta leading to an increase in the thickness of tunica media layer.

Endothelium-dependent vasorelaxant effects of praeruptorin a in isolated rat thoracic aorta

ABSTRACT Praeruptorin A (PA) is a natural coumarin compound from the roots of Radix Peucedani and is commonly used in the treatment of certain respiratory diseases and hypertension. Although previous studies identified relaxant effects of PA on tracheal and arterial preparations, little is known about its vasodilative effects and underlying mechanisms. Here, an organ bath system and tension recording methods were used to prepare and analyze isolated rat thoracic aorta artery rings. Aorta artery rings were pre-contracted with phenylephrine and then incubated with PA, and the possible mechanism of relaxation was investigated by adding inhibitors of nitric oxide synthase (NG-nitro-L-arginine methyl ester, L-NAME), endothelial nitric oxide synthase (L-NG-nitroarginine, L-NNA), cyclooxygenase (indomethacin), guanylyl cyclase (1 H-[1,2,4]oxadiazolo [4,3-a]quinoxalin-1-one, ODQ), and KCa channels (tetraethylammonium, TEA). Our study showed that PA-induced vasodilation was blocked by L-NAME, L-NNA, and ODQ, while CaCl2-induced vasoconstriction was countered by PA. Thus, PA may exert a vasodilatory effect by influencing the amounts of endothelium-derived relaxing factors through endothelial-dependent NO-cGMP and prostacyclin pathways (such as NO and prostacyclin 2). In the rat thoracic aorta, PA reduces vasoconstriction by inhibiting Ca2+ inflow.

Biomechanical and structural responses of the aorta to intermittent hypobaric hypoxia in a rat model

High altitude hypoxia is a condition experienced by diverse populations worldwide. In addition, several jobs require working shifts where workers are exposed to repetitive cycles of hypobaric hypoxia and normobaric normoxia. Currently, few is known about the biomechanical cardiovascular responses of this condition. In the present study, we investigate the cycle-dependent biomechanical effects of intermittent hypobaric hypoxia (IHH) on the thoracic aorta artery, in terms of both structure and function. To determine the vascular effects of IHH, functional, mechanical and histological approaches were carried out in the thoracic aorta artery, using uniaxial, pre-stretch, ring opening, myography, and histological tests. Three groups of rats were established: control (normobaric normoxia, NN), 4-cycles of intermittent hypoxia (short-term intermittent hypobaric hypoxia, STH), and 10-cycles of intermittent hypoxia (long-term intermittent hypobaric hypoxia, LTH). The pre-stretch and ring opening tests, aimed at quantifying residual strains of the tissues in longitudinal and circumferential directions, showed that the hypoxia condition leads to an increase in the longitudinal stretch and a marked decrease of the circumferential residual strain. The uniaxial mechanical tests were used to determine the elastic properties of the tissues, showing that a general stiffening process occurs during the early stages of the IH (STH group), specially leading to a significative increase in the high strain elastic modulus (E_{2}) and an increasing trend of low strain elastic modulus (E_{1}). In contrast, the LTH group showed a more control-like mechanical behavior. Myography test, used to assess the vasoactive function, revealed that IH induces a high sensitivity to vasoconstrictor agents as a function of hypoxic cycles. In addition, the aorta showed an increased muscle-dependent vasorelaxation on the LTH group. Histological tests, used to quantify the elastic fiber, nuclei, and geometrical properties, showed that the STH group presents a state of vascular fibrosis, with a significant increase in elastin content, and a tendency towards an increase in collagen fibers. In addition, advanced stages of IH (LTH), showed a vascular remodeling effect with a significant increase of internal and external diameters. Considering all the multidimensional vascular effects, we propose the existence of a long-term passive adaptation mechanism and vascular dysfunction as cycle-dependent effects of intermittent exposures to hypobaric hypoxia.

First report on Phyllobothrium delphini infection and Crassicauda sp. parasitism resulting in osseous metaplasia in a Cuvier's beaked whale (Ziphius cavirostris) from the Brazilian region.

A female Cuvier's Beaked Whale (Ziphius cavirostris) specimen measuring 580 cm in length died after being stranded in Southeastern Brazil. Following a necropsy, organ samples were obtained, fixed in 10% neutral buffered formalin and histopathologically analyzed. A severe and generalized hypodermis infection by Phyllobothrium delphini (Phyllobothriidae) was observed, resulting in granulomatous panniculitis. Severe renal and arterial lesions were also noted, including a severe bone metaplasia in the aorta artery, associated with a massive infection by Crassicauda sp, (Tetrameridae). A significant thoracic hemorrhage due to thoracic aorta artery rupture was noted, also likely due to this infection, resulting in a fatal injury. This study contributes towards knowledge on histopathologic changes in the scarcely studied Cuvier's Beaked Whale, is the first to associate a Crassicauda sp. infection in this whale species in the Brazilian region and also the first to indicate a resulting osseous metaplasia due to this parasitism and granulomatous dermatitis associated with Phyllobothrium delphini. Furthermore, this is also, to the best of our knowledge, the first report of Phyllobothrium delphini cysts in a Ziphius cavirostris specimen to date.

OP.3D.05] HYPERTENSION AND VASCULAR INJURY

Objective: C -type natriuretic peptide (CNP) and nitric oxide (NO) have effects on the endothelium and the vascular smooth muscle and are considered to be two major factors involved in the regulation of blood pressure and cardiovascular homeostasis. Growing evidence shows that the expression and release of a number of inflammatory cytokines are increased in hypertension and are also present at sites of vascular injury. In addition, pro-inflammatory cytokines such as tumoral necrosis factor alpha (TNF-α) and interleukin 1 (IL-1) stimulate the release of C-type natriuretic peptide (CNP), showing a potential role of CNP as a modulator of the inflammatory process. The aim of the present study was to evaluate the effects of CNP chronic treatment on vascular NO system, oxidative stress and inflammation in spontaneously hypertensive rats (SHR). Design and method: 12-week-old male Wistar and SHR were infused with CNP (0.75 μg/hr) or saline (S) (osmotic pumps, 14 days). Systolic blood pressure (SBP, mmHg) was recorded by tail-cuff method. After treatment, animals were decapitated and the thoracic aorta artery was removed to determine: protein expression of endothelial NO synthase (eNOS, % relative to actin density) and its phosphorylation in Ser1177 (% relative to eNOS density) by Western blot, superoxide anion production (O2.-, AU/mg dry weight) using lucigenine, content of thiobarbituric acid reactive species (TBARS, nmol/mg protein), IL-6 and TNF-α (% of staining area) by immunohistochemistry, and IL-1β (pg/mg protein) by ELISA. Statistics: 2 way ANOVA, Bonferroni test ad hoc or t test. n = 6 rats/group except IL-1β: n = 3 rats/group. Results: Results are expressed as mean ± SEM.Conclusions: Conclusions: Our results show that CNP chronic treatment attenuates the expression of pro-inflammatory markers and oxidative stress in vascular tissue of hypertensive rats. Also, CNP enhances NO system and induces a drop in blood pressure. These beneficial effects could be related to an overall improvement of target organ damage in this model of hypertension.

Layer-specific residual deformations and uniaxial and biaxial mechanical properties of thoracic porcine aorta

In this paper we hypothesize that the layer-separated residual stresses and mechanical properties of layer-separated thoracic aorta arteries may be dependent on arterial location of the vessel. To demonstrate any possible position differences, we measured the axial pre-stretch and opening angle and performed uniaxial and biaxial tests under physiological loads to study the mechanical behavior of both intact and layer-separated porcine aortic samples taken from thoracic region. In addition, we also provided constitutive parameters for each layer that can be used by biomedical engineers for investigating better therapies and developing artery-specific devices.We found that the opening angle for whole artery and adventitia layer are smaller and intima greater for proximal segments than for the distal thoracic ones. For the axial pre-stretch, our results showed significant increased values of the stretch ratios with location. We found that lower thoracic samples are stiffer than upper ones with the most important differences corresponding to those between the proximal and distal behaviors in the circumferential direction. The anisotropy represented by the different circumferential and longitudinal response is more remarkable in lower thoracic aorta. Finally, adventitia and intima samples present a tendency to be stiffer and more isotropic than the corresponding media samples in both directions for upper thoracic aorta and to be more anisotropic for lower thoracic aorta.

Development of second-generation small-molecule RhoA inhibitors with enhanced water solubility, tissue potency, and significant in vivo efficacy.

RhoA, a member of the Rho GTPases, is involved in a variety of cellular functions and could be a suitable therapeutic target for the treatment of cardiovascular diseases. However, few small-molecule RhoA inhibitors have been reported. Based on our previously reported lead compounds, 32 new 2-substituted quinoline (or quinoxaline) derivatives were synthesized and tested in biological assays. Six compounds showed high RhoA inhibitory activities, with IC50 values of 1.17-1.84 μM. Among these, (E)-3-(3-(ethyl(quinolin-2-yl)amino)phenyl)acrylic acid (26 b) and (E)-3-(3-(butyl(quinolin-2-yl)amino)phenyl)acrylic acid (26 d) demonstrated noticeable vasorelaxation effects against phenylephrine-induced contraction in thoracic aorta artery rings, and compound 26 b had good water solubility and showed significant in vivo efficacy, which was similar to that of 5-(1,4-diazepane-1-sulfonyl)isoquinoline (fasudil) in a subarachnoid hemorrhage-cardiovascular model. To the best of our knowledge, compound 26 b is the first example of a small- molecule RhoA inhibitor with potent in vivo efficacy, which could serve as a good lead for designing cardiovascular agents.

Investigation of Mechanisms Involved in (−)‐Borneol‐Induced Vasorelaxant Response on Rat Thoracic Aorta

The monoterpene (-)-borneol is present in essential oils of several medicinal plants. The aim of this study was to evaluate (-)-borneol effects on rat thoracic aorta artery rings. The cumulative addition of (-)-borneol (10(-9) -3 × 10(-4) M) on a phenylephrine-induced pre-contraction (10(-6) M) promoted a vasorelaxant effect in a concentration-dependent manner and independent of vascular endothelium. A similar effect was obtained on KCl-induced pre-contractions (80 mM). (-)-Borneol (10(-5) -3 × 10(-4 ) M) inhibited contractions induced by cumulative addition of CaCl2 (10(-6) -3 × 10(-2) M) in depolarizing medium without Ca(2+) in a concentration-dependent manner. On S-(-) Bay K 8644-induced pre-contractions (10(-7) M), (-)-borneol did not induce significant changes compared with KCl-induced pre-contractions. In a Ca(2+) -free medium, (-)-borneol (10(-5) , 10(-4) or 10(-3) M) interfered in calcium mobilization from phenylephrine (10(-6) M)- or caffeine (20 mM)-sensitive intracellular stores. The involvement of K(+) channels was evaluated by tetraethylammonium (3 mM), 4-aminopyridine (1 mM) and glibenclamide (10(-5) M) pre-treatment, and (-)-borneol-induced vasorelaxation was markedly attenuated. Thus, this vasorelaxant effect can probably be attributed to calcium influx blockade through voltage-operated calcium channels (CaV L), calcium mobilization from intracellular stores and potassium channels activation.

Design and Synthesis of Small Molecule RhoA Inhibitors: A New Promising Therapy for Cardiovascular Diseases?

RhoA is a member of Rho GTPases, a subgroup of the Ras superfamily of small GTP-binding proteins. RhoA, as an important regulator of diverse cellular signaling pathways, plays significant roles in cytoskeletal organization, transcription, and cell-cycle progression. The RhoA/ROCK inhibitors have emerged as a new promising treatment for cardiovascular diseases. However, to date, RhoA inhibitors are macromolecules, and to our knowledge, small molecular-based inhibitors have not been reported. In this study, a series of first-in-class small molecular RhoA inhibitors have been discovered by using structure-based virtual screening in conjunction with chemical synthesis and bioassay. Virtual screening of ∼200,000 compounds, followed by SPR-based binding affinity assays resulted in three compounds with binding affinities to RhoA at the micromolar level (compounds 1-3). Compound 1 was selected for further structure modifications in considering binding activity and synthesis ease. Fourty-one new compounds (1, 12a-v, 13a-h, and 14a-j) were designed and synthesized accordingly. It was found that eight (12a, 12j, 14a, 14b, 14d, 14e, 14 g, and 14h) showed high RhoA inhibition activities with IC(50) values of 1.24 to 3.00 μM. A pharmacological assay indicated that two compounds (14g and 14 h) demonstrated noticeable vasorelaxation effects against PE-induced contraction in thoracic aorta artery rings and served as good leads for developing more potent cardiovascular agents.

Migração de fio de Kirschner transfixando artéria aorta torácica ascendente

The orthopedic metallic pins and wires migration for the chest cavity is uncommon and rarely reported in medical literature although it is potentially lethal, especially when they reach the heart or mediastinum great vessels. We reported a case of Kirschner wire withdrawal, for right postero-lateral thoracotomy, which were transfixating ascendent thoracic aorta artery, in its due to its migration of left clavicle, where it was placed to fix an occurred fracture 10 years before.

Remodeling of the guinea pig intrinsic cardiac plexus with chronic pressure overload

Chronic pressure overload (PO) is associated with cardiac hypertrophy and altered autonomic control of cardiac function, in which the latter may involve adaptations in central and/or peripheral cardiac neural control mechanisms. To evaluate the specific remodeling of the intrinsic cardiac nervous system following pressure overload, the descending thoracic aorta artery of the guinea pig was constricted approximately 20%, and the animals recovered for 9 wk. Thereafter, atrial neurons of the intrinsic cardiac plexus were isolated for electrophysiological and immunohistochemical analyses. Intracellular voltage recordings from intrinsic cardiac neurons demonstrated no significant changes in passive membrane properties or action potential depolarization compared with age-matched controls and sham-operated animals, but afterhyperpolarization duration was increased in PO animals. Neuronal excitability, as determined by the number of action potentials produced with depolarizing stimuli, was differentially increased in phasic neurons derived from PO animals in response to exogenously applied histamine compared with sham and age-matched controls. Conversely, pituitary adenylate cyclase-activating polypeptide-induced increases in intrinsic cardiac neuron evoked AP frequency were similar between control and PO animals. Immunohistochemical analysis demonstrated a twofold increase in the percentage of neurons immunoreactive for neuronal nitric oxide synthase in PO animals compared with control. The density of mast cells within the intrinsic cardiac plexus from PO animals was also increased twofold compared with preparations from control animals. These results indicate that congestive heart failure associated with chronic pressure overload induces a differential remodeling of intrinsic cardiac neurons and upregulation of neuronal responsiveness to specific neuromodulators.

Fast age‐related on‐transient contraction kinetics during alpha1‐ adrenergic phenylephrine stimulation in rat thoracic aortae artery

Does the threecomponent empirical exponential mathematical model (3C) fit properly the aorta phenylephrine (phen) induced contraction data (APCD), identifying three "expected" phases (3Ps: P1, P2, and P3) of developing Force (P1F, P2F, and P3F) of contraction and kinetically characterize (K) them in terms of time constant (tau in s: P1Ftau, P2Ftau, and P3Ftau) in rat thoracic aorta artery (TAA)? and, are there significant kinetic (tau) differences between young (Y) and old (O) Wistar rats?. Y (230‐280 g bw; 8 weeks old, n= 8 ) and O (200‐250 g bw; 16‐18 weeks old, n= 7) groups TAA tissue rings bath on‐transient isometric (OnTI) contraction data of response, were fitted by means of nonlinear regression techniques with 3C to assess their kinetics (tau, MeanResponseTime in s) from a baselineonset to offset stimulation with 1 · 106 M phen.The 3C properly fitted, OnTI APCD in Y and O data; i) identifying 3FPs: the rapid one response (P1F), the moderately fast response (P2F), and the slow response (P3F); ii) K them as follows: P1Ftau &lt; P2Ftau&lt; P3Ftau in either Y or O arteries, and; the values from the 3FPs (except from P1Ftau), and MRT resulted significantly different between Y and O for P1Ftau (Y_7.17±3.04 similar to O_9.10±3.60, s), P2Ftau (Y_ 98.94±13.34&lt; O_69.96±14.12, s), P3Ftau (Y_291.68± 12.70&lt; 202.51±14.52,s), and MRT (Y_137.37±26.66&gt; O_116.77±16.46, s). These findings showed fast age‐related OnTI contraction kinetics phen induced in TAA.

Renal and Vascular Nitric Oxide System in Reduced Renal Mass Saline Hypertension

Background: Reduction in renal mass is associated with several structural and functional adaptations including compensatory renal growth and hemodynamic changes. The mediators of the renal hemodynamic adaptations have not been definitively identified. Several investigators have postulated that nitric oxide (NO) is involved this physiological mechanisms. The purpose of this study was to evaluate the role of vascular and renal NO pathway in the model of subtotal nephrectomy-salt load hypertension. Materials and Methods: Wistar rats with 75% renal mass reduction (RMR) and saline load were studied during 4 weeks. Weekly, indirect systolic blood pressure (SBP) were measured. One week after nephrectomy, animals were divided in two groups, hypertensive (SBP > 140 mm Hg) and normotensive (SBP < 140 mm Hg). Urinary excretion of nitrates and nitrites (NOx), urinary chemioluminiscence levels and NOS activity in the left kidney and in the thoracic aorta artery were determined at the fourth week after subtotal nephrectomy. Results: Urinary excretion of sodium was higher in normotensive rats than hypertensive rats and in both groups this parameter was higher than in sham rats. NOx excretion and NOS activity in the different nephron segments were higher in normotensive rats than in the hypertensive ones. In contrast, NOS activity in aorta sections and urinary chemiluminescence levels in hypertensive animals were enhanced compared with normotensive rats. These parameters were higher in both groups of nephrectomized rats than in sham ones. Conclusion: This study provides evidence to support the fact that the activation of the renal NO system is an important mechanism whereby the remnant kidney regulates sodium and water balance, contributing to control the arterial blood pressure in the renal mass reduction and saline load model.

Quantitative HPLC analysis of human plaque proteins in coronary and thoracic aorta arteries

Quantitative HPLC analysis of saline-soluble proteins obtained from human coronary and thoracic aorta plaque and from whole internal mammary artery were performed. Protein extracts were characterized by anion exchange and reverse-phase HPLC and the integrated chromatographs revealed significant differences in both peak retention times and areas for protein species from coronary artery compared to thoracic aorta artery plaque. Coronary artery plaque proteins possessed a high degree of cationic charge and polarity compared to those present in thoracic aorta plaque and normal mammary artery. This suggests that specific protein markers may be expressed in plaque of different anatomical origin, and that the processing of protein may be distinct to plaque sites. In contrast, characterization of molecular weight by gel electrophoresis resolved no major differences between plaque types. These findings indicate that proteins in human plaque lesions of different anatomical origin can be resolved by HPLC methodology and that they exhibit different charge and polarity. Such an HPLC approach may prove useful in the quantitative identification and ultimate isolation of specific protein markers present in plaque during atherogenesis, and in the study of mechanisms of protein involvement in plaque formation.