Objective      To observe the effect of serum amyloid P component (SAP) deficiency on atherosclerosis（AS）in mice.       Methods      Apolipoprotein E (ApoE) and SAP knockout mice served as an experimental group (n=12) and ApoE knockout mice served as a control group (n=12). Their average body weight was about 20 g at the age of 8 weeks. The animals were then fed with high fat diet and killed at the age of 16 weeks. Blood

heart

and thoracico-abdominal aorta tissue samples were taken. Serum lipid was analyzed and the AS lesion Plaque area was measured after oil red O staining.       Results      The HDL-C level was significantly higher while the LDL-C/HDL-C value and atherogenic index（AI）were significantly lower in experimental group than in control group（P0.01）. However

no significant difference was observed in TC

TG and LDL-C levels between the two groups（P0.05）. Oil red O staining showed that SAP deficiency significantly reduced the area of atherosclerosis plaques in heart and thoracico-abdominal aorta tissue samples（P0.01）.       Conclusion      SAP deficiency inhibits formation of atherosclerosis plaques in mice by up-regulating their HDL-C level.