Letter to the Editor
Vitamin E Limits AAA
To the Editor:
We read with interest the report of Gavrila and associates describing the effectiveness of Vitamin E in reducing AAA progression in the ApoE−/− Ang II model.1 The data presented clearly support the growing consensus that oxidative stress plays an integral role in AAA disease in human and animal models. In their discussion they also credit our laboratory with making the first observation of the effectiveness of Vitamin E in limiting rodent AAA progression three years ago.2 In describing our experiments, however, they apparently misunderstood our methodology; on page 1675 they state that “… just 3 rats were treated with Vitamin E.”
In our 2002 report we used Vitamin E on two separate rat cohorts: one for purposes of determining the efficacy of Vitamin E on AAA diameter (9 Vitamin E rats, 9 vehicle infusion), and one to determine ROS production via lucigenin chemiluminescence (10 additional Vitamin E rats, euthanized at 3 separate time points). These numbers were sufficient to reach the levels of statistical significance reported in the article. Because it was not specified in the manuscript we are uncertain as to how Dr Garvila determined our sample size. On page 2018 under “Methods: Study Groups”, in describing the third part of the multi-staged experiment, our text does state that “In experiment 3, rats were given either Vitamin E … in vehicle or vehicle alone….” Taken in context, however, this statement clearly does not state the number of rodents who received Vitamin E.
We appreciate the work that Dr Gavrila and associates have performed in confirming our prior observations and extending them to complementary animal models. Thank you for the opportunity to place both reports in proper perspective.
Gavrila D, Li WG, McCormick ML, Thomas M, Daugherty A, Cassis LA, Miller FJ Jr, Oberley LW, Dellsperger KC, Weintraub NL. Vitamin E inhibits abdominal aortic aneurysm formation in angiotensin II-infused apolipoprotein E-deficient mice. Arterioscler Thromb Vasc Biol. 2005; 25: 1671–1677.
Nakahashi TK, Hoshina K, Tsao PS, Sho E, Sho M, Karwowski JK, Yeh C, Yang RB, Topper JN, Dalman RL. Flow loading induces macrophage antioxidative gene expression in experimental aneurysms. Arterioscler Thromb Vasc Biol. 2002; 22: 2017–2022.