Atherogenesis in white carneau pigeons. Effects of low-level cholestane-triol feeding

Cholesterol auto-oxides have been shown to be angiotoxic in vivo and in vitro. Whether this toxicity is itself an atherogenic risk factor has not been established. In this study White Carneau pigeons were gavage-fed either 0.05% pure cholesterol or 0.05% pure cholesterol with trace levels of cholestane-triol (cholestane-3 beta,5 alpha,6 beta-triol) for 3 months. These are amounts similar to estimated U.S. dietary intake levels. Aortic lipids, aortic calcium and coronary artery histopathology were assessed. Aortic total cholesterol, cholesterol ester, and cholesterol ester/cholesterol ratio were: 1.87 vs 1.70 mg/g, 1.23 vs 1.01 mg/g, and 25 vs 26% for the cholesterol vs cholesterol + triol groups, respectively. These values are similar to published values at this duration and level of cholesterol feeding and are not statistically significantly different from each other. Aortic accumulation of calcium in the cholesterol + triol group was 1.16 +/- 0.35 mg/g, whereas in the cholesterol-fed group it was 0.82 +/- 0.27 mg/g, an increase of 42% (P greater than 0.02). Coronary artery atherosclerosis, as measured by percent mean lumenal stenosis, was 5.23% +/- 5.4, in the cholesterol + triol group as compared to 2.80% +/- 1.4 in the cholesterol group, an increase of 87% (P less than 0.01). These results suggest that dietary exposure to low levels of cholestane-triol, is atherogenic to a greater degree than exposure to pure cholesterol alone.