No effect of cyclooxygenase inhibition on plaque size in atherosclerosis-prone mice.

Objective: To study the role of cyclooxygenase (COX) inhibition on the development of advanced atherosclerosis in apolipoprotein E-deficient (apoE(-/-)) mice.

Design: Sixty apoE(-/-) mice were divided into three groups: a control group, a group fed standard mouse chow supplemented with 0.0067% (wt/wt) MF Tricyclic (selective COX-2 inhibitor), and a group fed the diet supplemented with 0.0134% (wt/wt) sulindac (non-selective COX inhibitor). Four months later, the mice were killed and the atherosclerotic plaque area in the aortic root was measured.

Results: Mean body weights did not differ at any time. The MF Tricyclic and sulindac groups had drug plasma levels of 1.31 +/- 0.11 and 0.84 +/- 0.23 micro g/ml, respectively. Plasma total cholesterol and triglyceride values were similar in all three groups. A small difference in plasma levels of high-density lipoprotein cholesterol was found between the groups (p = 0.03). Advanced atherosclerotic plaques were present in mice from all three groups, but there was no difference in mean plaque size between the groups (p = 0.9).

Conclusion: Neither selective COX-2 nor non-selective COX inhibition influenced the development of advanced atherosclerosis in apoE(-/-) mice.