RESUMO
OBJECTIVE: Factor V Leiden (FvL) causing activated protein C resistance is a genetic risk factor for venous thrombosis in humans, and it's effect on atherosclerosis is controversial. We evaluated the effect of FvL mutation on atherosclerosis in apolipoprotein E deficient mice fed with normal diet. METHODS: Degree of atherosclerosis and tissue fibrin deposition were determined in Fv+/+ApoE-/-, FvQ/+ApoE-/- and FvQ/QApoE-/- mice. RESULTS: In the presence of ApoE deficiency, homozygous FvL significantly increased atherosclerosis coverage in ApoE-/- mice (FvQ/QApoE-/- vs. Fv+/+ApoE-/-=5.0%+/-1.1% vs. 2.2%+/-0.4%, P<0.005) and tissue fibrin deposition in atherosclerotic lesion (FvQ/QApoE-/- vs. Fv+/+ApoE-/-=3.4% +/- 0.5% vs. 1.8%+/-0.4%, P<0.05). The atherosclerotic lesion of FvQ/+ApoE-/- mice was intermediate between FvQ/Q ApoE-/- and Fv+/+ApoE-/-, and there was no significant difference comparing with any of them. CONCLUSIONS: These observations demonstrate that homozygous FvL could promote atherosclerosis and fibrin deposition in apolipoprotein E deficient mice suggesting that Factor V mutation could be an important genetic risk factor for the enhanced atherosclerosis in human.