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Query: UMLS:C0004153 (atherosclerosis)
 77,401 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Coronary artery disease (CAD) is the consequence of atherosclerosis, a vascular disorder that is the leading cause of death and disability throughout much of the developed world. Certain cellular changes in the vulnerable atherosclerotic plaque are characterized by a loss of normal calcium regulation. This observation has led to interest in a potential antiatherogenic role for calcium channel blockers (CCBs), independent of their effects on vasodilation. The Prospective Randomized Evaluation of the Vascular Effects of Norvasc Trial (PREVENT) demonstrated that treatment with amlodipine, a third-generation CCB, in patients with documented CAD produced marked reductions in cardiovascular events as compared with placebo, without a reduction in coronary luminal loss. Amlodipine therapy was also associated with significant slowing in carotid atherosclerosis, an important surrogate marker for CAD, independent of blood pressure changes. The findings from PREVENT were remarkably consistent with another study known as the Coronary Angioplasty Amlodipine Restenosis Study (CAPARES). A reduction in the progression of carotid atherosclerosis has also been recently reported for lacidipine, another third-generation dihydropyridine CCB. These clinical findings have led to a renewed interest in potential plaque stabilization properties of certain CCBs, as will be systematically reviewed in this article. It is also probable that vascular protective agents, such as amlodipine may work in a synergistic fashion with other established treatments, including HMG-CoA reductase inhibitors, to effectively improve outcomes in patients who are at risk for or have established CAD.
Atherosclerosis 2002 Dec
PMID:Mechanisms of plaque stabilization for the dihydropyridine calcium channel blocker amlodipine: review of the evidence. 1241 68

Reactive oxygen metabolites and oxidized fatty acids are proinflammatory and are involved in the pathophysiology of atherosclerosis. Amlodipine, a unique third-generation dihydropyridine-type calcium channel blocker, seems to exert atheroprotective effects through its antioxidant properties related to its chemical structure and independent of its calcium channel-blocking effect. In this study, the interactions of amlodipine with major cellular antioxidants were investigated in order to elucidate the mechanisms underlying its atheroprotective effects. New Zealand white male rabbits were fed regular chow (group 1), chow with 1% cholesterol (group 2), regular chow plus 5 mg/kg/day amlodipine per os (group 3) and 1% cholesterol plus amlodipine (group 4) for 8 weeks. Total cholesterol, malondialdehyde (MDA) and vitamin E concentrations and catalase and superoxide dismutase (SOD) activities were determined in blood drawn before and after the experimental period. Aortic tissue was examined for atherosclerotic changes and aortic total cholesterol, MDA, catalase and SOD were determined. At the end of the 8-week treatment period, serum total cholesterol and plasma MDA were elevated in groups 2 and 4. In group 2, serum vitamin E and plasma SOD diminished (p < 0.05) and catalase increased (p < 0.05). In group 4, SOD activity increased at the end of treatment. MDA levels were lower and plasma SOD activities were higher in group 4 than in group 2. Aortic tissue investigations revealed higher total cholesterol and MDA concentrations and catalase activities in group 2 than in group 4, and the highest tissue SOD activity was recorded in group 4 (p < 0.05 for all comparisons). Morphological examination of aortic tissues exhibited endothelial disarrangement and lipid deposition in group 2. Histopathological alterations related to atherogenesis were less in group 4 than in group 2. Amlodipine seems to exert atheroprotective effects by reducing aortic cholesterol accumulation and blood and aortic lipid peroxidation, enhancing SOD activity both in blood and aortic tissue and suppressing the consumption of vitamin E. On the other hand, the suppression of catalase activity in blood and the aorta interferes with the drug's well-known antioxidant effects.
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PMID:Effects of the calcium channel blocker amlodipine on serum and aortic cholesterol, lipid peroxidation, antioxidant status and aortic histology in cholesterol-fed rabbits. 1256 88

This study was designed to investigate the potential antiatherosclerotic effects of the calcium antagonist amlodipine as compared with the HMG-CoA reductase inhibitor atorvastatin and the combination of both in ApoE*3-Leiden transgenic mice. Four groups of 15 ApoE*3-Leiden mice were put on a high-cholesterol diet. One group received 0.002% (wt/wt) amlodipine in the diet, which had no effect on plasma cholesterol levels. Another group received 0.01% (wt/wt) atorvastatin, resulting in a decrease of plasma cholesterol by 50% by a reduction in very low density lipoprotein production. The combination group received both amlodipine and atorvastatin. After 28 weeks, atherosclerosis in the aortic root was quantified. Treatment with amlodipine had no significant effect on atherosclerotic lesion area, whereas atorvastatin markedly reduced atherosclerosis by 77% compared with the control group. Atorvastatin also reduced inflammation markers. The combination of amlodipine and atorvastatin tended to reduce lesion area by 61% compared with the atorvastatin-only group; however, this effect did not reach statistical significance. Amlodipine treatment significantly reduced calcification in the lesions, whereas atorvastatin alone had no effect. The combination of amlodipine and atorvastatin resulted in a near absence of calcium deposits in the lesions. This study demonstrates that amlodipine treatment alone does not significantly reduce atherosclerotic lesion development. Atorvastatin was shown to have strong antiatherosclerotic effects, and cotreatment with amlodipine may potentiate the antiatherosclerotic effect of atorvastatin.
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PMID:Differential effects of amlodipine and atorvastatin treatment and their combination on atherosclerosis in ApoE*3-Leiden transgenic mice. 1282 28

Probably the most significant advance in cardiovascular medicine over the last two decades has been the identification of endothelial cells as a vasoactive organ. The endothelium plays a primary autocrine/paracrine regulatory role by secreting substances that control both vascular tone and structure. The dysfunctioning endothelium, which is characteristic of essential hypertension and most of the cardiovascular risk factors, is a major promoter for atherothrombosis and, consequently, cardiovascular treatment. One of most relevant mechanisms of endothelial dysfunction is oxidative stress production, which causes nitric oxide breakdown. The clinical manifestations of atherosclerosis are by far the prevailing cause of morbidity and mortality in hypertensive patients. Various clinical studies have shown the beneficial effects of calcium channel blockers on endothelial dysfunction. The potential mechanism by which calcium channel antagonists could exert their beneficial activity on endothelial dysfunction is very unlikely to be a calcium-dependent mechanism since endothelial cells do not express voltage-operated calcium channels. Experimental evidence suggests that calcium channel antagonists exert an anti-oxidant effect and therefore could protect endothelial cells against free-radical injury. Nifedipine is the calcium channel blocker, which improves endothelial nitric oxide availability, antagonises endothelin 1, restores endothelial permeability and low-density lipoprotein deposition. Calcium antagonists have demonstrated anti-atherogenic properties in various dinical studies. Calcium antagonists--in addition to their primary action in lowering blood pressure influence numerous cellular process involved in early atherogenesis. All calcium channel blockers do not offer same benefit of reversal of endothelial dysfunction. Amlodipine does not seem to be as effective as nifedipine in terms of atheroprotection. With nifedipine, the overall risk of cardiovascular events decreased significantly. Therefore, nifedipine (long-acting formulation) remains the first choice calcium channel blocker in cardiovascular therapeutics--today and tomorrow.
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PMID:Endothelium, atherosclerosis and calcium channel blockers. 1474 81

Amlodipine has been reported to improve endothelial function in patients with arterial hypertension and to significantly limit the progression of carotid atherosclerosis. The aim of this study was to assess the total antioxidant activity of amlodipine. We measured the in vitro antioxidant activity of amlodipine as its ability to antagonize the oxidation of alpha-keto-gamma-methiolbutyric acid by both hydroxyl and peroxyl radicals. The results are expressed as Total Oxyradical Scavenging Capacity (TOSC) units. Reduced glutathione, uric acid and trolox were used as the reference antioxidants. Amlodipine showed an efficiency as scavenger of peroxyl radicals (TOSC: 5945 +/- 544 units/mg) significantly higher (>50%, P <0.001) than that of GSH (2733 +/- 636 units/mg), and 70% lower (P < 0.0001) than the value obtained with uric acid (18144 +/- 696 units/mg) and trolox (17522 +/- 734 units/mg). Of interest, the scavenging capacity of amlodipine towards hydroxyl radicals (1455 +/- 154 units/mg) was 320% higher (P < 0.00001) than that of GSH (358 +/- 112 units/mg), 20% higher than that of uric acid (1198 +/- 121 units/mg), and 100% higher than that of trolox (759 +/- 143 units/mg). Amlodipine has intrinsic antioxidant activity with both anti-hydroxyl and anti-peroxyl radicals activity.
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PMID:An in vitro study of the peroxyl and hydroxyl radical scavenging capacity of the calcium antagonist amlodipine. 1546 69

In order to evaluate some pleiotropic effects of cardilopin (Amlodipine, EGIS Pharmaceuticals) 33 ambulatory patients were examined. During the 2-month study period on the background of cardilopin treatment there were positive changes in some parameters of coronary atherosclerosis. Pleiotropic effects of cardilopin were particularly expressed in restoring of endothelial function and inhibition of platelet aggregation. There was found tendency to reduce the degree of hyperlipoperoxidemia related to oxidative stress. Obtained results of the present trial support the use of cardilopin in all coronary heart disease patients with or without myocardial revascularization and arterial hypertension.
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PMID:Pleiotropic effects of cardilopin (secondary coronary prevention). 1583 80

Long-acting dihydropyridine calcium channel blockades have been shown to limit the progression of atherosclerosis and decrease the incidence of cardiovascular events in humans and animals. To investigate the vasoprotective effects beyond the blood pressure-lowering effects of these agents, amlodipine (20 mg/kg/ day) and manidipine (10 mg/kg/day) were administered by gavage to N(G)-nitro-L-arginine methyl ester (L-NAME)-induced hypertensive rats for 2 weeks. L-NAME treatment (0.7 mg/ml in drinking water) significantly decreased the gene and protein expression of endothelial nitric oxide synthase (eNOS) and increased nicotinamide adenine dinucleotide phosphate (NADPH) oxidase, vascular cell adhesion molecule-1 (VCAM-1), and monocyte chemoattractant protein-1 (MCP-1) mRNA levels in the aorta, as determined by Western blotting and reverse transcription (RT)-polymerase chain reaction (PCR). Amlodipine and manidipine normalized the decreased expression of eNOS gene and protein, and attenuated the overexpression of NADPH oxidase, VCAM-1, and MCP-1 mRNA. Furthermore, amlodipine and manidipine prevented the L-NAME-induced increase in the angiotensin converting enzyme (ACE) mRNA content, thereby restoring control levels in the aorta. On the other hand, hydralazine treatment had no such effect in L-NAME treated rats. Furthermore, the increased expression of manganese superoxide dismutase (Mn-SOD) by L-NAME treatment was not affected by amlodipine, manidipine, or hydralazine. We concluded that the direct anti-inflammatory and antioxidative effects of calcium channel blockades in the aorta of rats with L-NAME-induced hypertension were not likely to have been mediated by the blood pressure-lowering action of these agents, but instead these beneficial effects appear to have been mediated by an augmentation of eNOS expression and by the inhibition of the expression of ACE.
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PMID:Calcium channel blockades exhibit anti-inflammatory and antioxidative effects by augmentation of endothelial nitric oxide synthase and the inhibition of angiotensin converting enzyme in the N(G)-nitro-L-arginine methyl ester-induced hypertensive rat aorta: vasoprotective effects beyond the blood pressure-lowering effects of amlodipine and manidipine. 1639 74

Hypertension is associated with increased risk of cardiovascular diseases. Antihypertensive treatment, particularly blockade of the renin-angiotensin system, contributes to prevent atherosclerosis-mediated cardiovascular events. Direct comparison of different antihypertensive treatments on atherosclerosis and particularly plaque stabilization is sparse. ApoE(-/-) mice with vulnerable (2-kidney, 1-clip renovascular hypertension model) or stable (1-kidney, 1-clip renovascular hypertension model) atherosclerotic plaques were used. Mice were treated with aliskiren (renin inhibitor), irbesartan (angiotensin-receptor blocker), atenolol (beta-blocker), or amlodipine (calcium channel blocker). Atherosclerosis characteristics were assessed. Hemodynamic and hormonal parameters were measured. Aliskiren and irbesartan significantly prevented atherosclerosis progression in 2-kidney, 1-clip mice. Indeed, compared with untreated animals, plaques showed thinner fibrous cap (P<0.05); smaller lipid core (P<0.05); decreased media degeneration, layering, and macrophage content (P<0.05); and increased smooth muscle cell content (P<0.05). Interestingly, aliskiren significantly increased the smooth muscle cell compared with irbesartan. Despite similar blood pressure lowering, only partial plaque stabilization was attained by atenolol and amlodipine. Amlodipine increased plaque smooth muscle cell content (P<0.05), whereas atenolol decreased plaque inflammation (P<0.05). This divergent effect was also observed in 1-kidney, 1-clip mice. Normalizing blood pressure by irbesartan increased the plasma renin concentration (5932+/-1512 ng/mL per hour) more than normalizing it by aliskiren (16085+/-5628 ng/mL per hour). Specific renin-angiotensin system blockade prevents atherosclerosis progression. First, evidence is provided that direct renin inhibition mediates atherosclerotic plaque stabilization. In contrast, beta-blocker and calcium channel blocker treatment only partially stabilize plaques differently influencing atherogenesis. Angiotensin II decisively mediates plaque vulnerability. The plasma renin concentration measurement by an indirect method did not confirm the excessive increase of plasma renin concentration reported in the literature during aliskiren compared with irbesartan or amlodipine treatment.
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PMID:Renin inhibition by aliskiren prevents atherosclerosis progression: comparison with irbesartan, atenolol, and amlodipine. 1839 Oct 92

Inflammation and increased capillary permeability is a significant aspect of the pathogenesis of many diseases including atherosclerosis. L-type calcium channel blockers (CCB) are commonly used as cardiovascular drugs. Amlodipine, lacidipine, and nicardipine were evaluated for anti-inflammatory activity on the paw oedema produced by carrageenan. The effect of these drugs was compared with the activity of indomethacin. Their effects on vascular permeability were also tested by hyaluronidase-induced capillary permeability. In our animal experiments, amlodipine decreased the carrageenan-induced paw oedema at doses of 1, 3, and 6 mg kg(-1) by 27.3%, 43.7%, and 67.3% four hour after carrageenan administration; the same doses of lacidipine and nicardipine decreased paw oedema by 37.1%, 55.6%, 76.4%, 11.2%, 31.0%, 91%; and indomethacin decreased oedema by 38.2% at a dose of 6 mg kg(-1). Lacidipine significantly inhibited the hyaluronidase-induced increase in capillary permeability at doses of 1, 3, and 6 mg kg(-1) compared with the control group. However, amlodipine and nicardipine significantly inhibited the hyaluronidase-induced increase in capillary permeability at 3 and 6 mg kg(-1) doses. A 6 mg kg(-1) dose of indomethacin significantly decreased the capillary permeability which was increased by hyaluronidase. These results suggest that CCBs can be efficient anti-inflammatories, and can also significantly decrease capillary permeability.
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PMID:Effects of calcium channel blockers on hyaluronidase-induced capillary vascular permeability. 1870 32

Alteration in transferring of calcium ions are seen in atherosclerotic cells and amlodipine can positively influence risk factors associated with atherosclerosis, but all mechanisms are not known. Recent studies indicate that endothelin-1 (ET-1) contributes to the atheroma formation and progression of atherosclerosis. In this study, we have evaluated the effects of amlodipine treatment and/or high-cholesterol diet on blood and carotid artery tissue concentration of ET-1 in the atherosclerotic rabbits. Thirty six male New Zealand white rabbits were randomly divided into four groups: normal-diet control (NC), normal-diet receiving amlodipine (NA), high-cholesterol diet (HC) and high-cholesterol diet receiving amlodipine (HA) groups. After 8 weeks all animals were anesthetized and blood or carotid tissue samples were colleted. Eight weeks of amlodipine treatment reduced significantly total cholesterol, LDL and TG in hypercholesterolemic (HA) group. Significant increase in plasma HDL-C and decrease in TG were the main effects of amlodipine treatment on serum lipid profiles in the control group. The plasma and carotid tissue levels of ET-1 in HC group were significantly increased as compared with the NC group (p<0.01). Amlodipine treatment significantly reduced ET-1 level in NA and HA rabbits (p<0.01). Furthermore, high-cholesterol diet induced atherosclerotic lesions as shown by the enhancement of endothelial cell diameter and accumulation of lipid droplets under endothelial cells. Amlodipine treatment reduced atherotic lesions in these rabbits. Amlodipine treatment reduced levels of total cholesterol, LDL and TG as well as plasma and carotid tissue levels of ET-1 in high lipid situation. We suggest that amlodipine treatment by reducing the ET-1 may contribute to reducing the progression of atherosclerotic disease.
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PMID:Amlodipine treatment decreases plasma and carotid artery tissue levels of endothelin-1 in atherosclerotic rabbits. 2054 20


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