title: Combined treatment with olmesartan medoxomil and amlodipine besylate attenuates atherosclerotic lesion progression in a model of advanced atherosclerosis.
abstract: BACKGROUND
  Besides their blood pressure-lowering effects, olmesartan medoxomil and amlodipine besylate exhibit additional anti-inflammatory mechanisms in atherosclerosic disease. Most of the studies investigating the effects of atherosclerosis focused on early atherosclerotic lesions, whereas lesions in human disease, at the time when medical treatment is started, are already well established. Therefore, we set up a model of advanced atherosclerosis and investigated the effects of olmesartan medoxomil, amlodipine besylate, and the combination of both on atherosclerotic lesion size and lesion composition.
  
  
  METHODS
  Olmesartan medoxomil (1 mg/kg/day), amlodipine besylate (1.5 mg/kg/day), and the combination of both was added to chow and was fed to apolipoprotein E-deficient (ApoE(-/-)) mice at 25 weeks of age. Mice were sacrificed after 25 weeks of drug administration and perfused with formalin. Innominate arteries were dissected out and paraffin embedded. Serial sections were generated, and lesion sizes and their composition - such as minimal thickness of the fibrous cap, size of the necrotic core, and presence of calcification - were analyzed. Electrophoretic mobility shift assays were used to detect DNA-binding activity of the transcription factor nuclear factor-kappa B (NF-κB) in aortic tissue.
  
  
  RESULTS
  Treatment with the combination of olmesartan medoxomil and amlodipine besylate led to a significant reduction in atherosclerotic lesion size in ApoE(-/-) mice (olmesartan medoxomil/amlodipine besylate: 122,277±6,795 μm(2), number [n]=14; versus control: 177,502±10,814 μm(2), n=9; P<0.001). Treatment with amlodipine besylate (n=5) alone did not reach significance. However, a trend toward a decrease in lesion size in the amlodipine besylate-treated animals could be observed. In the histological analysis of atherosclerotic lesion composition, significantly thicker fibrous caps were found in treatment with amlodipine besylate (amlodipine: 5.12±0.26 μm, n=6; versus control: 3.98±0.18 μm, n=10; P<0.01). Furthermore, all sections revealed morphological signs of calcification, but no difference could be detected. Treatment with the combination of olmesartan medoxomil and amlodipine besylate showed no effect on lesion composition. Electrophoretic mobility shift assays of nuclear extracts demonstrated reduced activity of the transcription factor NF-κB when treated with olmesartan medoxomil, amlodipine besylate, or their combination, as compared to controls.
  
  
  CONCLUSIONS
  Combined treatment with olmesartan medoxomil and amlodipine besylate attenuated atherosclerotic lesion progression, possibly due to anti-inflammatory mechanisms. Our data support the hypothesis that even in advanced atherosclerosis anti-inflammatory treatment, using angiotensin II type 1 receptor blockers and calcium channel antagonists of the dihydropyridine type can attenuate atherosclerotic lesion progression.
authors.affiliation: Department of Internal Medicine III, University of Heidelberg, Heidelberg, Germany.
authors.forename: Philipp
authors.initials: P
authors.lastname: Sievers
authors.affiliation: Institute of Medical Biometry and Informatics, University of Heidelberg, Heidelberg, Germany.
authors.forename: Lorenz
authors.initials: L
authors.lastname: Uhlmann
authors.affiliation: Department of Cardiac Surgery, University of Heidelberg, Heidelberg, Germany.
authors.forename: Sevil
authors.initials: S
authors.lastname: Korkmaz-Icöz
authors.affiliation: Department of Internal Medicine III, University of Heidelberg, Heidelberg, Germany.
authors.forename: Christian
authors.initials: C
authors.lastname: Fastner
authors.affiliation: Department of Internal Medicine III, University of Heidelberg, Heidelberg, Germany.
authors.forename: Florian
authors.initials: F
authors.lastname: Bea
authors.affiliation: Department of Internal Medicine III, University of Heidelberg, Heidelberg, Germany.
authors.forename: Erwin
authors.initials: E
authors.lastname: Blessing
authors.affiliation: Department of Internal Medicine III, University of Heidelberg, Heidelberg, Germany.
authors.forename: Hugo A
authors.initials: HA
authors.lastname: Katus
authors.affiliation: Department of Internal Medicine III, University of Heidelberg, Heidelberg, Germany.
authors.forename: Michael R
authors.initials: MR
authors.lastname: Preusch
mesh_terms: D000068558:Amlodipine Besylate, Olmesartan Medoxomil Drug Combination / Q000008:administration & dosage / Q000494:pharmacology*; D047228:Angiotensin II Type 1 Receptor Blockers / Q000008:administration & dosage / Q000494:pharmacology*; D000818:Animals; D001057:Apolipoproteins E / Q000235:genetics*; D050197:Atherosclerosis / Q000188:drug therapy* / Q000473:pathology; D004195:Disease Models, Animal; D018450:Disease Progression; D024202:Electrophoretic Mobility Shift Assay; D005260:Female; D051379:Mice; D008810:Mice, Inbred C57BL; D018345:Mice, Knockout; D016328:NF-kappa B / Q000378:metabolism
chemical_list: D000068558:Amlodipine Besylate, Olmesartan Medoxomil Drug Combination; D047228:Angiotensin II Type 1 Receptor Blockers; D001057:Apolipoproteins E; D016328:NF-kappa B
keywords: AT1 receptor blocker; ApoE; NF-κB; advanced atherosclerosis; calcium channel antagonist; inflammation