title: Low-level laser irradiation inhibits abdominal aortic aneurysm progression in apolipoprotein E-deficient mice.
abstract: OBJECTIVE
  Increased early detection of abdominal aortic aneurysm (AAA) and the severe complications of its current treatment have emphasized the need for alternative therapeutic strategies that target pathogenetic mechanisms of progression and rupture. Recent in vitro studies from our laboratory have shown that low-level laser irradiation (LLLI) (780 nm) modifies cellular processes fundamental to aneurysm progression. The present study was designed to determine whether LLLI retards the progression of suprarenal AAA in vivo.
  
  
  RESULTS
  High-frequency ultrasonography (0.01 mm resolution) was used to quantify the effect of LLLI on aneurysmatic aortic dilatation from baseline to 4 weeks after subcutaneous infusion of angiotensin II by osmotic minipumps in the apolipoprotein E-deficient mouse. At 4 weeks, seven of 15 non-irradiated, but none of the 13 LLLI, mice had aneurysmal dilatation in the suprarenal aneurysm-prone segments that had progressed to >or=50% increase in maximal cross-sectional diameter (CSD) over baseline (P = 0.005 by Fisher's exact test). The mean CSD of the suprarenal segments (normalized individually to inter-renal control segments) was also significantly lower in irradiated animals (LLLI vs. non-irradiated: 1.32 +/- 0.14 vs. 1.82 +/- 0.39, P = 0.0002 by unpaired, two-tailed t-test) with a 94% reduction in CSD at 4 weeks compared with baseline. M-mode ultrasound data showed that reduced radial wall velocity seen in non-treated was significantly attenuated in the LLLI mice, suggesting a substantial effect on arterial wall elasticity.
  
  
  CONCLUSIONS
  These in vivo studies, together with previous in vitro studies from this laboratory, appear to provide strong evidence in support of a role for LLLI in the attenuation of aneurysm progression. Further studies in large animals would appear to be the next step towards testing the applicability of this technology to the human interventional setting.
authors.affiliation: Department of Anatomy, The Hebrew University-Hadassah Medical School, PO Box 12272, Jerusalem 91120, Israel.
authors.forename: Lilach
authors.initials: L
authors.lastname: Gavish
authors.forename: Chen
authors.initials: C
authors.lastname: Rubinstein
authors.forename: Atilla
authors.initials: A
authors.lastname: Bulut
authors.forename: Yacov
authors.initials: Y
authors.lastname: Berlatzky
authors.forename: Ronen
authors.initials: R
authors.lastname: Beeri
authors.forename: Dan
authors.initials: D
authors.lastname: Gilon
authors.forename: Leah
authors.initials: L
authors.lastname: Gavish
authors.forename: Mickey
authors.initials: M
authors.lastname: Harlev
authors.forename: Petachia
authors.initials: P
authors.lastname: Reissman
authors.forename: S David
authors.initials: SD
authors.lastname: Gertz
mesh_terms: D000804:Angiotensin II / Q000008:administration & dosage; D000818:Animals; D017544:Aortic Aneurysm, Abdominal / Q000000981:diagnostic imaging / Q000209:etiology / Q000532:radiotherapy*; D001057:Apolipoproteins E / Q000172:deficiency* / Q000235:genetics; D004108:Dilatation, Pathologic / Q000000981:diagnostic imaging; D006801:Humans; D028022:Low-Level Light Therapy; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D018345:Mice, Knockout; D014463:Ultrasonography
chemical_list: D001057:Apolipoproteins E; D000804:Angiotensin II