title: Contrast Ultrasound Imaging of the Aorta Does Not Affect Progression of Atherosclerosis or Cardiovascular Biomarkers in ApoE-/- Mice.
abstract: OBJECTIVE
  Ultrasound contrast agents (UCAs) enhance cardiovascular ultrasound imaging. Adverse biological effects have occurred after administration of UCAs, and more research is needed for a comprehensive understanding of the risks involved. We used the ApoE(-/-) mouse model of atherosclerosis to characterize the effects of ultrasound and UCAs on atherosclerosis and plasma biomarkers.
  
  
  METHODS
  Male ApoE(-/-) mice (8 weeks old; n = 24) were intravenously infused with a UCA (2 × 10(10) Definity microbubbles per hour; Lantheus Medical Imaging, North Billerica, MA) and exposed to 2.8-MHz center frequency ultrasound (10 Hz pulse repetition frequency, 1.4 microseconds pulse duration, 2 minutes exposure duration, and 2 sites) at 1 of 3 derated peak rarefactional pressure amplitudes (0, 1.9, or 3.8 MPa), and then consumed either a chow or Western diet for 4 weeks (n = 4 per group). Blood plasma samples were collected before ultrasound exposure and at 2 and 4 weeks after exposure and assayed for total cholesterol and von Willebrand Factor (vWF). A pathologist measured atheroma thickness in formalin-fixed, hematoxylin-eosin-stained transverse aorta sections and scored them for severity of atherosclerosis.
  
  
  RESULTS
  Plasma total cholesterol initially averaged 286 mg/dL in the Western diet group and increased to 861 mg/dL after 4 weeks on the diet (P < .0001). Total cholesterol did not increase significantly in the chow diet group. Plasma vWF increased after 2 weeks on the Western diet (P < .0001). Atheroma thickness was greater in animals consuming the Western diet than in chow-fed animals (P < .05). Ultrasound had no significant effect on plasma total cholesterol, plasma vWF, or atheroma thickness.
  
  
  CONCLUSIONS
  Contrast ultrasound did not increase the severity of atherosclerosis or alter cardiovascular biomarkers in the ApoE(-/-) mouse model.
authors.affiliation: Bioacoustics Research Laboratory, Department of Electrical and Computer Engineering (B.W.S., S.S., R.J.M., W.D.O.), Division of Nutritional Sciences (B.W.S., J.W.E., W.D.O.), and Departments of Statistics (D.G.S.), Pathology (S.S.), and Food Science and Human Nutrition (J.W.E.), University of Illinois at Urbana-Champaign, Urbana, Illinois USA.
authors.forename: Brendon W
authors.initials: BW
authors.lastname: Smith
authors.affiliation: Bioacoustics Research Laboratory, Department of Electrical and Computer Engineering (B.W.S., S.S., R.J.M., W.D.O.), Division of Nutritional Sciences (B.W.S., J.W.E., W.D.O.), and Departments of Statistics (D.G.S.), Pathology (S.S.), and Food Science and Human Nutrition (J.W.E.), University of Illinois at Urbana-Champaign, Urbana, Illinois USA.
authors.forename: Douglas G
authors.initials: DG
authors.lastname: Simpson
authors.affiliation: Bioacoustics Research Laboratory, Department of Electrical and Computer Engineering (B.W.S., S.S., R.J.M., W.D.O.), Division of Nutritional Sciences (B.W.S., J.W.E., W.D.O.), and Departments of Statistics (D.G.S.), Pathology (S.S.), and Food Science and Human Nutrition (J.W.E.), University of Illinois at Urbana-Champaign, Urbana, Illinois USA.
authors.forename: Sandhya
authors.initials: S
authors.lastname: Sarwate
authors.affiliation: Bioacoustics Research Laboratory, Department of Electrical and Computer Engineering (B.W.S., S.S., R.J.M., W.D.O.), Division of Nutritional Sciences (B.W.S., J.W.E., W.D.O.), and Departments of Statistics (D.G.S.), Pathology (S.S.), and Food Science and Human Nutrition (J.W.E.), University of Illinois at Urbana-Champaign, Urbana, Illinois USA.
authors.forename: Rita J
authors.initials: RJ
authors.lastname: Miller
authors.affiliation: Bioacoustics Research Laboratory, Department of Electrical and Computer Engineering (B.W.S., S.S., R.J.M., W.D.O.), Division of Nutritional Sciences (B.W.S., J.W.E., W.D.O.), and Departments of Statistics (D.G.S.), Pathology (S.S.), and Food Science and Human Nutrition (J.W.E.), University of Illinois at Urbana-Champaign, Urbana, Illinois USA.
authors.forename: John W
authors.initials: JW
authors.lastname: Erdman
authors.affiliation: Bioacoustics Research Laboratory, Department of Electrical and Computer Engineering (B.W.S., S.S., R.J.M., W.D.O.), Division of Nutritional Sciences (B.W.S., J.W.E., W.D.O.), and Departments of Statistics (D.G.S.), Pathology (S.S.), and Food Science and Human Nutrition (J.W.E.), University of Illinois at Urbana-Champaign, Urbana, Illinois USA. wdo@uiuc.edu.
authors.forename: William D
authors.initials: WD
authors.lastname: O'Brien
mesh_terms: D000818:Animals; D001011:Aorta / Q000000981:diagnostic imaging*; D001057:Apolipoproteins E; D050197:Atherosclerosis / Q000000981:diagnostic imaging*; D015415:Biomarkers / Q000097:blood; D002318:Cardiovascular Diseases / Q000097:blood; D003287:Contrast Media / Q000009:adverse effects*; D018450:Disease Progression; D008297:Male; D051379:Mice; D014463:Ultrasonography
chemical_list: D001057:Apolipoproteins E; D015415:Biomarkers; D003287:Contrast Media
keywords: atherosclerosis; biomarkers; cardiovascular disease; contrast agents; endothelium; microbubbles; ultrasound