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(Circulation. 2001;103:448.)
© 2001 American Heart Association, Inc.
Basic Science Reports |
From the Division of Cardiology, Department of Medicine, Atlanta VA Medical Center and Emory University School of Medicine, Atlanta, Ga.
Correspondence to W. Robert Taylor, MD, PhD, Cardiology Division, Emory University School of Medicine, 1639 Pierce Dr, Suite 319 WMB, Atlanta, GA 30322. E-mail wtaylor{at}emory.edu
| Abstract |
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|
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Methods and ResultsAngiotensin II (0.7 mg · kg-1 · d-1 SC) was administered to apoE-deficient mice via osmotic minipumps. The animals were placed on either standard chow or an atherogenic diet. After 8 weeks, the mean atherosclerotic lesion area in the descending thoracic and abdominal aortas of animals on a standard chow diet was 0.4±0.1% compared with 5.2±1.2% in those animals maintained on an atherogenic diet (P<0.0001). In angiotensin IItreated animals on standard chow, the mean lesion area was increased to 11.0±2.3%, which was further increased to 69.9±9.4% (P<0.0001) in angiotensin IItreated animals on an atherogenic diet. Similar findings were obtained when tissues from the ascending aorta were analyzed. At 8 weeks in mice receiving a standard chow diet, angiotensin II dramatically increased the atherosclerotic lesion area by 840±83 µm2 (P<0.0001). Animals on a high-fat diet had a similar marked increase in lesion area in response to angiotensin II (217±19 µm2, P<0.0001). In contrast, when hypertension was induced with norepinephrine, only a modest effect on the atherosclerotic lesion area was observed.
ConclusionsAngiotensin IIinduced hypertension specifically increased the development of atherosclerosis in apoE knockout mice. This response was seen in animals receiving either standard chow or an atherogenic diet. These studies demonstrate the profound effect of angiotensin II on the development of atherosclerosis.
Key Words: apolipoproteins angiotensin hypertension atherosclerosis
| Introduction |
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Hypertension presents a complex biological stimulus to the arterial wall. The ultimate response of the arterial wall to hypertension is likely the synthesis of both mechanical and humoral stimuli. The mechanical effects of elevated blood pressure on the arterial wall are not well understood. Elevated blood pressure increases wall stress in a nonuniform distribution.3 4 Increased wall stress has been proposed to be a proinflammatory stimulus,5 as evidenced by the association between mechanical strain and the production of reactive oxygen species6 7 and the expression of inflammatory gene products.8 9 10 Indeed, wall stress has been shown to be a biologically relevant stimulus for the development of atherosclerosis.11
In addition, the cellular components of the arterial wall are exposed to multiple neurohumoral signals that are undoubtedly altered in hypertension. Several lines of evidence have specifically implicated the reninangiotensin II system in the pathogenesis of atherosclerosis.12 13 14 15 First, the cellular consequences of angiotensin II stimulation are potentially proatherogenic. Angiotensin II stimulation results in the production of reactive oxygen species as well as increased expression of proinflammatory gene products.14 16 Given the acknowledged role of oxidative stress and vascular inflammation in atherosclerosis,17 these effects of angiotensin II are likely mechanistically relevant to the development and progression of atherosclerotic lesions. Second, studies performed in several experimental models of atherosclerosis indicate that either inhibition of ACE activity or blockade of angiotensin type 1 receptors results in a decrease in the development of atherosclerotic lesions.18 19 20 21 Finally, numerous studies in humans have shown that high renin forms of hypertension are particularly proatherogenic and that patients with high renin hypertension are at increased risk of myocardial infarction.22 23 24 25 The recently presented results of the Heart Outcomes Prevention Evaluation (HOPE) trial demonstrated a remarkable decrease in cardiovascular morbidity and mortality when normotensive individuals at increased risk for cardiovascular events were treated with an ACE inhibitor.26 Taken together, these data specifically implicate the reninangiotensin II system in the pathogenesis of atherosclerosis.
The primary goal of the present study was to define the specific importance of angiotensin IIinduced hypertension in the development of atherosclerosis. We used apoE-deficient mice that were made hypertensive through the use of a continuous infusion of angiotensin II. We found that angiotensin IIinduced hypertension dramatically accelerated the initiation and progression of atherosclerotic lesions. Conversely, when hypertension was induced to a similar level by the administration of norepinephrine, we found only a modest increase in atherosclerosis. These data demonstrate the extremely potent proatherogenic effects of angiotensin II in apoE-deficient mice and provide further support for the hypothesis that angiotensin II is mechanistically relevant in the pathogenesis of atherosclerosis.
| Methods |
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The animals were fed ad libitum and had free access to water. The animals were housed and cared for according to the guidelines proposed by the National Institutes of Health (NIH) for the care and use of experimental animals (NIH publication No. 85-23).
Some mice received angiotensin II infusions via a
subcutaneously implanted osmotic minipump (Alzet, model 1002) for 4 or
8 weeks. The mice were anesthetized with 375 mg/kg
2,2,2-tribromoethanol (Avertin, Sigma Chemical Co). An osmotic pump
containing angiotensin II dissolved in a solution of 0.15 mol/L NaCl
and 0.01N acetic acid at a concentration calculated to deliver
0.7
mg · kg-1 · d-1
of drug was inserted into a subcutaneous pocket. The dose of
angiotensin II was selected on the basis of previous studies in our
laboratories10 and provides a
plasma concentration of angiotensin II similar to that reported in
patients with renovascular hypertension.
An additional group of animals was treated with norepinephrine in a similar manner.10 The concentration of norepinephrine in the osmotic pump was adjusted to yield a dose of 5.6 mg · kg-1 · d-1.
Systolic blood pressure28 was measured during treatment and before euthanizing the animals at the end of each experiment by using a computerized, noninvasive, tail-cuff system (BP 2000 Visitech Systems). One set of 10 measurements was obtained for each animal, and the mean blood pressure was calculated. Animals were habituated to the device before measuring the pressures to ensure accurate measurements.
Evaluation of Atherosclerotic Lesions and
Histological Analysis
The animals were euthanized by
CO2 inhalation at the prescribed time points.
The heart and aorta were pressure-perfused with 0.9% sodium chloride
solution, followed by pressure fixation at
100 mm Hg with a 4%
formaldehyde solution.
To evaluate the extent of atherosclerotic lesion formation, 2 approaches were used. The descending thoracic and abdominal aorta was analyzed en face, whereas the ascending aorta was reserved for microscopic analysis.29 These complementary approaches allowed us to obtain information about disease extent as well as lesion complexity. The descending thoracic and abdominal aortas were opened longitudinally and stained with oil red O (Sigma) as previously described.30 Photographs of the stained specimens were digitized for data analysis. The luminal lesion surface area was quantified by using NIH Image software (version 1.65) with custom macros. Data were expressed as the percentage of the descending aorta with positive oil red O staining.
The hearts and aortas were embedded in paraffin, and 5-µm-thick serial sections were prepared. Every 10th section was stained with hematoxylin and eosin. For quantification of luminal cross-sectional area involved by atherosclerotic plaque in the ascending aorta, digital images of the stained sections obtained at the level of the aortic valve were obtained. The atherosclerotic lesions were manually traced on the computer. Care was taken to exclude normal-appearing media and to include only the intimal/subintimal atherosclerotic lesions. Data were expressed as total lesion area of the cross section.
Statistical Analysis
All data are given as mean±SEM. Statistical
significance was determined by ANOVA. Post hoc analysis was performed
by the Duncan New Multiple Range
Test.
| Results |
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Effects of Angiotensin II Infusion on the
Development and Extent of Atherosclerosis in ApoE-Deficient
Animals
Angiotensin IIinduced hypertension had a dramatic
effect on the development of atherosclerosis in the descending thoracic
and abdominal aorta. Representative examples of en face preparations of
the descending thoracoabdominal aorta after 8 weeks of treatment are
shown in
Figure 1
. Note that regions of atherosclerosis appear white
because these images were obtained before staining with oil red O. In
the angiotensin IItreated animals on the atherogenic diet, the
descending thoracic and abdominal aortas were almost completely covered
with atherosclerotic lesions. Importantly, compared with the control
animals, the angiotensin IItreated animals on the normal chow diet
also exhibited a marked worsening in the degree of atherosclerosis
(Figure 2
).
|
|
The proximal ascending aorta was also examined for evidence
of accelerated atherogenesis in the angiotensin IItreated
apoE-deficient animals. Compared with no treatment, the angiotensin II
treatment resulted in a dramatic increase in atherosclerosis of the
ascending aorta in the apoE-deficient animals on regular chow or the
atherogenic diet
(Figure 3
).
|
Effects of Angiotensin II Infusion on
Atherosclerosis in Wild-Type Animals
Wild-type animals made hypertensive with angiotensin II
that were fed either a standard chow or atherogenic diet did not
develop atherosclerotic lesions after 8 weeks of treatment. Therefore,
additional animals were treated for a total of 12 weeks. However, even
after 12 weeks, angiotensin IItreated wild-type animals did not
develop atherosclerotic lesions.
Figure 4
shows a representative en face preparation of the
descending thoracic and abdominal aorta obtained from a wild-type
animal maintained on an atherogenic diet and treated with angiotensin
II for 12 weeks. No atherosclerotic lesions were seen in the ascending
thoracic aorta of wild-type mice treated with angiotensin II and
maintained on either diet.
|
Effect of Norepinephrine-Induced Hypertension
on Development and Extent of Atherosclerosis in ApoE-Deficient
Animals
To gain insight into the relative contributions of high
blood pressure and angiotensin II, per se, we used norepinephrine
infusion as an alternate model of hypertension. Mean systolic blood
pressures for these animals are given in
Table 3
. Note that the degree of hypertension induced in
the norepinephrine-treated animals was similar to that obtained in the
angiotensin IItreated animals.
|
We found that compared with angiotensin IIinduced
hypertension, norepinephrine-induced hypertension had a modest effect
on the development of atherosclerosis.
Figure 5
shows a representative example of the descending
thoracic and abdominal aorta of an apoE-deficient animal made
hypertensive with norepinephrine and maintained on an atherogenic diet
for 8 weeks. In the ascending aorta, there was no significant effect of
norepinephrine-induced hypertension on the atherosclerotic lesion area
(Figure 6
). Whereas norepinephrine significantly increased
the development of atherosclerosis in the descending thoracic and
abdominal aorta, the magnitude of the increase was far less than that
seen with angiotensin IIinduced hypertension
(Figure 2
).
|
|
To gain insight into the potential role of mononuclear
inflammation in this process, we stained paraffin-embedded sections of
the ascending aorta with a murine macrophagespecific antibody
(Figure 7
). The most intense staining occurred in the
angiotensin IItreated animals. There was evidence of a marked
macrophage infiltration of the atherosclerotic lesions as well as the
adventitia.
|
| Discussion |
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The effects of angiotensin II administration on atherosclerotic lesion development in both the ascending and descending aorta were evident after only 4 weeks of treatment. In normotensive apoE-deficient animals receiving regular chow, it has been previously reported that fatty streak formation occurs in the proximal ascending aorta at no earlier than 10 weeks of age.31 The advanced, complicated, fibroproliferative plaque associated with severe luminal stenosis of coronary arteries has been reported to appear at 25 to 40 weeks of age in apoE-deficient mice fed the western-type diet.31 Clearly, the development of complex atherosclerotic lesions in the angiotensin IItreated animals after only 4 to 8 weeks of treatment represents a marked acceleration of the disease process.
Previous studies have implicated the renin-angiotensin system in the pathogenesis of atherosclerosis. Observational studies in humans have demonstrated that patients with high levels of circulating renin are at increased risk for myocardial infarction and other atherosclerotic cardiovascular events.1 22 23 24 25 32 In addition, studies in several different models of atherosclerosis have shown that ACE inhibitors and angiotensintype 1 receptor antagonists inhibit atherosclerotic lesion formation.18 19 20 21
The mechanism whereby angiotensin IIinduced hypertension accelerates and worsens atherosclerosis is probably multifactorial. Angiotensin II has direct effects on the cellular components of the arterial wall.15 In addition, there may be effects on the arterial wall related to the resultant mechanical forces that occur as a result of elevated blood pressure.5 We have demonstrated that although norepinephrine-induced hypertension did accelerate the development of atherosclerosis in apoE-deficient animals, the magnitude of the response was markedly less than that seen with angiotensin IIinduced hypertension. Therefore, the data in the present study indicate that the dramatic proatherogenic effects of angiotensin II infusion are largely due to the humoral effects of angiotensin II and not the mechanical effects of elevated blood pressure.
Angiotensin II has several relevant direct and indirect humoral effects that may be involved in the pathogenesis of atherosclerosis. Indirect mechanisms include alterations in sympathetic outflow, aldosterone secretion, and prostaglandins.33 A central component of angiotensin II signaling is the generation of reactive oxygen species. Angiotensin II activates the NAD(P)H oxidase in cultured vascular smooth muscle cells,16 which results in the generation of reactive oxygen species. This oxidase has been functionally linked to the development of vascular hypertrophy in response to angiotensin II34 and the generation of an inflammatory response in vascular smooth muscle cells.15 35 Our finding of a dense macrophage infiltration of the arterial wall in the angiotensin IItreated animals suggests that this process may be relevant to the findings reported in the present study. Angiotensin II also upregulates thrombin receptor expression in the aortic tissues of rats via a redox-sensitive mechanism.36 This appears to occur via the generation of reactive oxygen species and is independent of the pressor effects of angiotensin II. Angiotensin also upregulates expression of monocyte chemoattractant protein-1 (MCP-1) in cultured vascular smooth muscle cells,37 which may occur through a redox-sensitive pathway. Thus, there are multiple potential humoral mechanisms involving the generation of reactive oxygen species through which angiotensin II could be proatherogenic.
Although our data demonstrate a dominant effect of the humoral components of angiotensin II stimulation on the development of atherosclerosis, the data obtained with norepinephrine-induced hypertension suggest that mechanical factors may also contribute significantly, albeit to a lesser degree. Mechanical deformation of vascular cells results in the upregulation of inflammatory mediators, such as MCP-1.8 9 10 Furthermore, in both angiotensin II and norepinephrine models of hypertension, expression of MCP-1 is upregulated in the aortic tissues.10 This is associated with increased infiltration of the arterial wall with monocytes/macrophages. Mechanical strain applied to both endothelial and vascular smooth muscle cells results in an increase in the production of reactive oxygen species,6 7 which have been implicated in the development of atherosclerosis.38 39 40 Mechanoregulation of reactive oxygen species may be an independent mechanism for the proatherogenic effect of hypertension, or reactive oxygen species may function through the upregulation of inflammatory gene products.2 41 Thus, there are several potential mechanisms whereby mechanical effects can contribute to the proatherogenic effects of hypertension.
The present study was performed with the use of an angiotensin II infusion model of hypertension. It is important to note that this is a model of a relatively rare form of hypertension. Thus, the relevance of the findings reported in the present study to the clinical syndrome of hypertension depends in part on the relative contributions of the humoral and mechanical aspects of this model. A potential mitigating factor is the role of the tissue-based components of the renin-angiotensin system. As evidenced by the antiatherogenic effects of agents that modulate the renin-angiotensin system,18 19 20 21 even in the absence of high systemic levels of angiotensin II, locally generated angiotensin II may have a significant impact on the development of atherosclerosis. The recent results of the HOPE trial suggest that angiotensin II may be involved in the development of atherosclerosis in individuals without high renin hypertension.26
After submission of the present article, Daugherty et al42 presented data demonstrating a similar proatherogenic effect of angiotensin II in apoE-deficient mice. Their results differ from ours in that they found that doses of angiotensin II similar to those that we used did not result in any increase in blood pressure. This discrepancy may be due to the use of general anesthesia during blood pressure measurements, the exclusive use of female animals, or the older age of the animals used in the studies of Daugherty et al. In addition, they reported the presence of abdominal aortic aneurysms in up to 33% of the animals infused with angiotensin II. We also noted occasional aneurysm formation but with a lower incidence. This difference may also be due to the difference in the age and sex of the animals studied.
The pathophysiology of human atherosclerotic disease is clearly multifactorial.43 Hypertension is a well-know risk factor for the development of atherosclerosis. We have shown that angiotensin IIinduced hypertension specifically accelerates the development of aortic atherosclerosis in apoE-deficient animals. These findings may provide insight into the relative importance of the renin-angiotensin system in the pathogenesis of atherosclerosis and provide a foundation for future studies to explore the mechanisms through which hypertension promotes the development of atherosclerosis.
| Acknowledgments |
|---|
Received May 3, 2000; revision received July 26, 2000; accepted July 28, 2000.
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J.-H. Oak and H. Cai Attenuation of Angiotensin II Signaling Recouples eNOS and Inhibits Nonendothelial NOX Activity in Diabetic Mice Diabetes, January 1, 2007; 56(1): 118 - 126. [Abstract] [Full Text] [PDF] |
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M. Ushio-Fukai and R. W. Alexander Caveolin-Dependent Angiotensin II Type 1 Receptor Signaling in Vascular Smooth Muscle Hypertension, November 1, 2006; 48(5): 797 - 803. [Full Text] [PDF] |
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R. Cui, B. Tieu, A. Recinos, R. G. Tilton, and A. R. Brasier RhoA Mediates Angiotensin II-Induced Phospho-Ser536 Nuclear Factor {kappa}B/RelA Subunit Exchange on the Interleukin-6 Promoter in VSMCs Circ. Res., September 29, 2006; 99(7): 723 - 730. [Abstract] [Full Text] [PDF] |
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C. Cheng, D. Tempel, R. van Haperen, A. van der Baan, F. Grosveld, M. J.A.P. Daemen, R. Krams, and R. de Crom Atherosclerotic Lesion Size and Vulnerability Are Determined by Patterns of Fluid Shear Stress Circulation, June 13, 2006; 113(23): 2744 - 2753. [Abstract] [Full Text] [PDF] |
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V. L. King, D. B. Trivedi, J. M. Gitlin, and C. D. Loftin Selective Cyclooxygenase-2 Inhibition With Celecoxib Decreases Angiotensin II-Induced Abdominal Aortic Aneurysm Formation in Mice Arterioscler. Thromb. Vasc. Biol., May 1, 2006; 26(5): 1137 - 1143. [Abstract] [Full Text] [PDF] |
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T. Godfraind Antioxidant effects and the therapeutic mode of action of calcium channel blockers in hypertension and atherosclerosis Phil Trans R Soc B, December 29, 2005; 360(1464): 2259 - 2272. [Abstract] [Full Text] [PDF] |
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V. L. Sales, G. K. Sukhova, M. A. Lopez-Ilasaca, P. Libby, V. J. Dzau, and R. E. Pratt Angiotensin Type 2 Receptor Is Expressed in Murine Atherosclerotic Lesions and Modulates Lesion Evolution Circulation, November 22, 2005; 112(21): 3328 - 3336. [Abstract] [Full Text] [PDF] |
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Y. Takata, V. Chu, A. R. Collins, C. J. Lyon, W. Wang, F. Blaschke, D. Bruemmer, E. Caglayan, W. Daley, J. Higaki, et al. Transcriptional Repression of ATP-Binding Cassette Transporter A1 Gene in Macrophages: A Novel Atherosclerotic Effect of Angiotensin II Circ. Res., October 28, 2005; 97(9): e88 - e96. [Abstract] [Full Text] [PDF] |
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J. Kyselovic, P. Martinka, Z. Batova, A. Gazova, and T. Godfraind Calcium Channel Blocker Inhibits Western-Type Diet-Evoked Atherosclerosis Development in ApoE-Deficient Mice J. Pharmacol. Exp. Ther., October 1, 2005; 315(1): 320 - 328. [Abstract] [Full Text] [PDF] |
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R. M.P. Arruda, V. A. Peotta, S. S. Meyrelles, and E. C. Vasquez Evaluation of Vascular Function in Apolipoprotein E Knockout Mice With Angiotensin-Dependent Renovascular Hypertension Hypertension, October 1, 2005; 46(4): 932 - 936. [Abstract] [Full Text] [PDF] |
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Y. Zhang, K. K. Griendling, A. Dikalova, G. K. Owens, and W. R. Taylor Vascular Hypertrophy in Angiotensin II-Induced Hypertension Is Mediated by Vascular Smooth Muscle Cell-Derived H2O2 Hypertension, October 1, 2005; 46(4): 732 - 737. [Abstract] [Full Text] [PDF] |
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L. Zuo, M. Ushio-Fukai, S. Ikeda, L. Hilenski, N. Patrushev, and R. W. Alexander Caveolin-1 Is Essential for Activation of Rac1 and NAD(P)H Oxidase After Angiotensin II Type 1 Receptor Stimulation in Vascular Smooth Muscle Cells: Role in Redox Signaling and Vascular Hypertrophy Arterioscler. Thromb. Vasc. Biol., September 1, 2005; 25(9): 1824 - 1830. [Abstract] [Full Text] [PDF] |
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A. C. Calkin, J. M. Forbes, C. M. Smith, M. Lassila, M. E. Cooper, K. A. Jandeleit-Dahm, and T. J. Allen Rosiglitazone Attenuates Atherosclerosis in a Model of Insulin Insufficiency Independent of Its Metabolic Effects Arterioscler. Thromb. Vasc. Biol., September 1, 2005; 25(9): 1903 - 1909. [Abstract] [Full Text] [PDF] |
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R. Matsui, S. Xu, K. A. Maitland, A. Hayes, J. A. Leopold, D. E. Handy, J. Loscalzo, and R. A. Cohen Glucose-6 Phosphate Dehydrogenase Deficiency Decreases the Vascular Response to Angiotensin II Circulation, July 12, 2005; 112(2): 257 - 263. [Abstract] [Full Text] [PDF] |
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J. P. Davies, C. Scott, K. Oishi, A. Liapis, and Y. A. Ioannou Inactivation of NPC1L1 Causes Multiple Lipid Transport Defects and Protects against Diet-induced Hypercholesterolemia J. Biol. Chem., April 1, 2005; 280(13): 12710 - 12720. [Abstract] [Full Text] [PDF] |
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S. Sola, M. Q.S. Mir, F. A. Cheema, N. Khan-Merchant, R. G. Menon, S. Parthasarathy, and B. V. Khan Irbesartan and Lipoic Acid Improve Endothelial Function and Reduce Markers of Inflammation in the Metabolic Syndrome: Results of the Irbesartan and Lipoic Acid in Endothelial Dysfunction (ISLAND) Study Circulation, January 25, 2005; 111(3): 343 - 348. [Abstract] [Full Text] [PDF] |
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A. Daugherty, D. L. Rateri, H. Lu, T. Inagami, and L. A. Cassis Hypercholesterolemia Stimulates Angiotensin Peptide Synthesis and Contributes to Atherosclerosis Through the AT1A Receptor Circulation, December 21, 2004; 110(25): 3849 - 3857. [Abstract] [Full Text] [PDF] |
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R. Elhage, P. Gourdy, L. Brouchet, J. Jawien, M.-J. Fouque, C. Fievet, X. Huc, Y. Barreira, J. C. Couloumiers, J.-F. Arnal, et al. Deleting TCR{alpha}{beta}+ or CD4+ T Lymphocytes Leads to Opposite Effects on Site-Specific Atherosclerosis in Female Apolipoprotein E-Deficient Mice Am. J. Pathol., December 1, 2004; 165(6): 2013 - 2018. [Abstract] [Full Text] [PDF] |
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S. Wassmann, T. Czech, M. van Eickels, I. Fleming, M. Bohm, and G. Nickenig Inhibition of Diet-Induced Atherosclerosis and Endothelial Dysfunction in Apolipoprotein E/Angiotensin II Type 1A Receptor Double-Knockout Mice Circulation, November 9, 2004; 110(19): 3062 - 3067. [Abstract] [Full Text] [PDF] |
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M. Ishibashi, K. Egashira, Q. Zhao, K.-i. Hiasa, K. Ohtani, Y. Ihara, I. F. Charo, S. Kura, T. Tsuzuki, A. Takeshita, et al. Bone Marrow-Derived Monocyte Chemoattractant Protein-1 Receptor CCR2 Is Critical in Angiotensin II-Induced Acceleration of Atherosclerosis and Aneurysm Formation in Hypercholesterolemic Mice Arterioscler. Thromb. Vasc. Biol., November 1, 2004; 24(11): e174 - e178. [Abstract] [Full Text] [PDF] |
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M. K. Whalin and W. R. Taylor Rounding up the usual suspects in atherosclerosis. Focus on "Growth factors induce monocyte binding to vascular smooth muscle" Am J Physiol Cell Physiol, September 1, 2004; 287(3): C592 - C593. [Full Text] [PDF] |
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L. Mazzolai, M. A. Duchosal, M. Korber, K. Bouzourene, J. F. Aubert, H. Hao, V. Vallet, H. R. Brunner, J. Nussberger, G. Gabbiani, et al. Endogenous Angiotensin II Induces Atherosclerotic Plaque Vulnerability and Elicits a Th1 Response in ApoE-/- Mice Hypertension, September 1, 2004; 44(3): 277 - 282. [Abstract] [Full Text] [PDF] |
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T. A. Henriques, J. Huang, S. S. D'Souza, A. Daugherty, and L. A. Cassis Orchidectomy, But Not Ovariectomy, Regulates Angiotensin II-Induced Vascular Diseases in Apolipoprotein E-Deficient Mice Endocrinology, August 1, 2004; 145(8): 3866 - 3872. [Abstract] [Full Text] [PDF] |
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K. K. Koh, J. W. Son, J. Y. Ahn, D. S. Kim, D. K. Jin, H. S. Kim, S. H. Han, Y.-H. Seo, W.-J. Chung, W. C. Kang, et al. Simvastatin Combined With Ramipril Treatment in Hypercholesterolemic Patients Hypertension, August 1, 2004; 44(2): 180 - 185. [Abstract] [Full Text] [PDF] |
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R. Candido, T. J. Allen, M. Lassila, Z. Cao, V. Thallas, M. E. Cooper, and K. A. Jandeleit-Dahm Irbesartan but Not Amlodipine Suppresses Diabetes-Associated Atherosclerosis Circulation, March 30, 2004; 109(12): 1536 - 1542. [Abstract] [Full Text] [PDF] |
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W. Ni, S. Kitamoto, M. Ishibashi, M. Usui, S. Inoue, K.-i. Hiasa, Q. Zhao, K.-i. Nishida, A. Takeshita, and K. Egashira Monocyte Chemoattractant Protein-1 Is an Essential Inflammatory Mediator in Angiotensin II-Induced Progression of Established Atherosclerosis in Hypercholesterolemic Mice Arterioscler. Thromb. Vasc. Biol., March 1, 2004; 24(3): 534 - 539. [Abstract] [Full Text] |
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A. Paul, K. W.S. Ko, L. Li, V. Yechoor, M. A. McCrory, A. J. Szalai, and L. Chan C-Reactive Protein Accelerates the Progression of Atherosclerosis in Apolipoprotein E-Deficient Mice Circulation, February 10, 2004; 109(5): 647 - 655. [Abstract] [Full Text] [PDF] |
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W. A. Hsueh and D. Bruemmer Peroxisome Proliferator-Activated Receptor {gamma}: Implications for Cardiovascular Disease Hypertension, February 1, 2004; 43(2): 297 - 305. [Abstract] [Full Text] [PDF] |
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K. K. Griendling and G. A. FitzGerald Oxidative Stress and Cardiovascular Injury: Part II: Animal and Human Studies Circulation, October 28, 2003; 108(17): 2034 - 2040. [Full Text] [PDF] |
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K. K. Koh, J. Y. Ahn, S. H. Han, D. S. Kim, D. K. Jin, H. S. Kim, M.-S. Shin, T. H. Ahn, I. S. Choi, and E. K. Shin Pleiotropic effects of angiotensin II receptor blocker in hypertensive patients J. Am. Coll. Cardiol., September 3, 2003; 42(5): 905 - 910. [Abstract] [Full Text] [PDF] |
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E. L. Schiffrin and R. M. Touyz Multiple actions of angiotensin II in hypertension: benefits of AT1 receptor blockade J. Am. Coll. Cardiol., September 3, 2003; 42(5): 911 - 913. [Full Text] [PDF] |
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M. R. Alexander, J. W. Knowles, T. Nishikimi, and N. Maeda Increased Atherosclerosis and Smooth Muscle Cell Hypertrophy in Natriuretic Peptide Receptor A-/-Apolipoprotein E-/- Mice Arterioscler. Thromb. Vasc. Biol., June 1, 2003; 23(6): 1077 - 1082. [Abstract] [Full Text] [PDF] |
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M. W. Manning, L. A. Cassis, and A. Daugherty Differential Effects of Doxycycline, a Broad-Spectrum Matrix Metalloproteinase Inhibitor, on Angiotensin II-Induced Atherosclerosis and Abdominal Aortic Aneurysms Arterioscler. Thromb. Vasc. Biol., March 1, 2003; 23(3): 483 - 488. [Abstract] [Full Text] [PDF] |
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N. Kawada, E. Imai, A. Karber, W. J. Welch, and C. S. Wilcox A Mouse Model of Angiotensin II Slow Pressor Response: Role of Oxidative Stress J. Am. Soc. Nephrol., December 1, 2002; 13(12): 2860 - 2868. [Abstract] [Full Text] [PDF] |
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F. E. Rey and P. J. Pagano The Reactive Adventitia: Fibroblast Oxidase in Vascular Function Arterioscler. Thromb. Vasc. Biol., December 1, 2002; 22(12): 1962 - 1971. [Abstract] [Full Text] [PDF] |
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A. R. Brasier, A. Recinos III, and M. S. Eledrisi Vascular Inflammation and the Renin-Angiotensin System Arterioscler. Thromb. Vasc. Biol., August 1, 2002; 22(8): 1257 - 1266. [Abstract] [Full Text] [PDF] |
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R. Candido, K. A. Jandeleit-Dahm, Z. Cao, S. P. Nesteroff;, W. C. Burns, S. M. Twigg, R. J. Dilley, M. E. Cooper, and T. J. Allen Prevention of Accelerated Atherosclerosis by Angiotensin-Converting Enzyme Inhibition in Diabetic Apolipoprotein E-Deficient Mice Circulation, July 9, 2002; 106(2): 246 - 253. [Abstract] [Full Text] [PDF] |
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W. A. Hsueh and R. E. Law PPAR{gamma} and Atherosclerosis: Effects on Cell Growth and Movement Arterioscler. Thromb. Vasc. Biol., December 1, 2001; 21(12): 1891 - 1895. [Abstract] [Full Text] [PDF] |
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R. Peila, L.R. White, H. Petrovich, K. Masaki, G.W. Ross, R.J. Havlik, L.J. Launer, and J. Poirier Joint Effect of the APOE Gene and Midlife Systolic Blood Pressure on Late-Life Cognitive Impairment: The Honolulu-Asia Aging Study Editorial Comment: The Honolulu-Asia Aging Study Stroke, December 1, 2001; 32(12): 2882 - 2889. [Abstract] [Full Text] [PDF] |
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H. D. Intengan and E. L. Schiffrin Vascular Remodeling in Hypertension: Roles of Apoptosis, Inflammation, and Fibrosis Hypertension, September 1, 2001; 38(3): 581 - 587. [Abstract] [Full Text] [PDF] |
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T. Watanabe, R. Pakala, T. Katagiri, and C. R. Benedict Synergistic Effect of Urotensin II With Mildly Oxidized LDL on DNA Synthesis in Vascular Smooth Muscle Cells Circulation, July 3, 2001; 104(1): 16 - 18. [Abstract] [Full Text] [PDF] |
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H. Sakamoto, M. Aikawa, C. C. Hill, D. Weiss, W. R. Taylor, P. Libby, and R. T. Lee Biomechanical Strain Induces Class A Scavenger Receptor Expression in Human Monocyte/Macrophages and THP-1 Cells : A Potential Mechanism of Increased Atherosclerosis in Hypertension Circulation, July 3, 2001; 104(1): 109 - 114. [Abstract] [Full Text] [PDF] |
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