Objective        To investigate the role of the 5-lipoxygenase pathway in atherosclerosis of ApoE knockout mice.       Methods        Twenty-four 8-week-old male ApoE

-/-

mice with body weight of 22.42±1.21 g were randomized into control group (n=12

normal diet) and atherosclerotic model group (n=12

high fat diet). After 16 weeks’ feeding

all animals were sacrificed. The corrected plaque areas (PA/LA) of the aortic were measured. The expression of 5-li

poxygenase at gene and protein levels in aorta were detected separately through RT-PCR and Western blotting. Serum levels of leukotriene B4 (LTB4) and leukotriene D4 (LTD4) were measured by ELISA.       Results        Atheromatous plaques were found in the atherosclerotic model group

indicating the successful establishment of the model. The expression of 5-LO at mRNA (0.61±0.05) and protein (1.53±0.18) levels in the aorta of atherosclerosis model group were obviously higher than those in the control group (0.18±0.03 and 0.52±0.40

P0.01). So were the serum levels of LTB4 (34.79±4.47 vs 12.07±2.35

P0.01) and LTD4 (2 862.48±48.77 vs 2 357.10±53.57

P0.01). The serum levels of LTB4 and LTD4 were positively correlated with the corrected plaque areas (r=0.954

P0.01

and r=0.946

P0.01).        Conclusion        The 5-lipoxygenase pathway may play a significant role in the pathogenesis of atherosclerosis in ApoE knockout mice.