Effects of aspirin on atherosclerosis and the cyclooxygenase-2 expression in atherosclerotic rabbits.
BACKGROUND
Atherosclerosis is a complex vascular inflammatory disease. Aspirin is a mainstay in the prevention of vascular complications of atherosclerosis. In this study, the effectiveness of aspirin in suppressing atherosclerosis and the inflammation process was evaluated in rabbits fed with a high fat diet.


METHODS
Eighteen male New Zealand rabbits were randomly divided into 3 groups: control group, untreated cholesterol-fed group, aspirin treated cholesterol-fed group, which were fed for 12 weeks. After 12 weeks, the aorta was harvested for pathologic morphology observation. Immunohistochemical analysis of cyclooxygenase-2 (COX-2), macrophage and vascular smooth muscle cell (VSMC) was performed. The statistical analysis was performed by the statistical program SPSS10.0.


RESULTS
The aorta plaque/intima size (P/I) by pathologic morphology observation was 0%, (59.6 +/- 13.7)% and (36.3 +/- 16.5)% in the control, untreated cholesterol-fed group and aspirin treated group, respectively. The maximum plaque thickness, the degree of artery stenosis and the proportion of the intimal circumference occupied by atheroma of the 3 groups were significantly different from each other (P < 0.01). The expression of COX-2 and macrophage in plaque of the aspirin treated group were decreased compared with that in untreated cholesterol-fed group. However, no difference was found in the expression of VSMC between the aspirin treated and the untreated cholesterol-fed group.


CONCLUSIONS
The mechanism of atherosclerosis suppression by aspirin in cholesterol-fed rabbits is related to the inhibition of COX-2 expression together with the reduced inflammation followed by, but not related to the hypolipidemic effects.
Guo
Yi
Y
Department of Neurology, Second Affiliated Hospital of Jinan University, Shenzhen 518020, China. yi_g4326@yahoo.com.cn
Wang
Qi-zhang
QZ
Tang
Bing-shan
BS
Zuo
Yan-fang
YF
Li
Fang-ming
FM
Jiang
Xin
X
Wang
Ling
L
Ma
Ke-fu
KF
D000818:Animals; D001011:Aorta / Q000473:pathology; D001241:Aspirin / Q000494:pharmacology*; D050197:Atherosclerosis / Q000473:pathology / Q000517:prevention & control*; D002791:Cholesterol, Dietary / Q000008:administration & dosage; D051546:Cyclooxygenase 2 / Q000032:analysis*; D007150:Immunohistochemistry; D008055:Lipids / Q000097:blood; D008297:Male; D011817:Rabbits
D002791:Cholesterol, Dietary; D008055:Lipids; D051546:Cyclooxygenase 2; D001241:Aspirin