Arrest of progression of pre-induced abdominal aortic aneurysm in apolipoprotein E-deficient mice by low level laser phototherapy.

Background And Objectives: Using non-invasive, high-frequency ultrasonography (HF-u/s), we showed that low-level laser phototherapy (LLL) inhibits de-novo formation of abdominal aortic aneurysms (AAA) in apolipoprotein-E-deficient (Apo-E(-/-)) mice. The current study tests the effect of LLL on the progression of pre-induced AAA.

Study Design/material And Methods: AAA was induced in Apo-E(-/-) mice (age 16-20 weeks) by subcutaneous infusion of angiotensin-II using osmotic minipumps (1000 ng/kg/minutes, 4 weeks).

Inadequate reinforcement of transmedial disruptions at branch points subtends aortic aneurysm formation in apolipoprotein-E-deficient mice.

Introduction: Infusion of angiotensin-II (Ang-II) in apolipoprotein-E-deficient mice (Apo-E(-/-)) results in suprarenal abdominal aortic aneurysm (AAA) in 30-85% of cases. This study identifies the apparent mechanism by which some animals do, but others do not, develop AAA in this model.

Methods: Male Apo-E(-/-) mice were infused with Ang-II (n=21) or saline (n=6) and sacrificed at 4 weeks.

Low level laser arrests abdominal aortic aneurysm by collagen matrix reinforcement in apolipoprotein E-deficient mice.

Background And Objectives: Recent in vitro studies by our group indicated that low level laser irradiation (LLLI) modifies cellular processes essential to the progression of abdominal aortic aneurysm (AAA). Using high-frequency ultrasonography (HF-u/s) in the angiotensin-II (Ang-II)-infused, apolipoprotein-E-deficient (Apo-E(-/-) ) mouse model of AAA, we found that LLLI markedly inhibited aneurysm formation and preserved arterial wall elasticity. We now report, using quantitative histopathology, the likely mechanism underlying the preventative effect of LLLI on aneurysm formation in this model.