Sidestream cigarette smoke accelerates atherogenesis in apolipoprotein E -/- mice

Epidemiological studies have strongly implicated active and passive smoking with increased risk of cardiovascular diseases. The present study was perf ormed to determine if exposure to sidestream cigarette smoke (SSCS), a surr ogate of environmental tobacco smoke, promotes atherogenesis in a mouse mod el of human atherosclerosis. Female ApoE-deficient mice, maintained on a We stern diet, were exposed to SSCS in a whole-body exposure chamber for a tot al of 6 h each day, 5 days a week for 7, 10 and 14 weeks. Animals exposed t o filtered ambient air served as controls. Elevated concentrations of blood carboxyhemoglobin and pulmonary CYP1A1 ascertained effective exposure of a nimals to SSCS. There were no consistent changes in serum concentrations of cholesterol between control and SSCS-exposed mice. Morphometric assessment of grossly discernible lesions covering the intimal area of aorta showed r emarkable increases in SSCS-exposed mice at all three exposure durations st udied. Increases in the lesion area defined by en face measurements were ac companied by parallel increases in the levels of esterified and unesterifie d cholesterol in the aortic tissues of SSCS mice. These results clearly dem onstrate promotion of atherosclerotic lesion development by tobacco smoke i n an atherosclerosis-susceptible mouse model. (C) 2001 Elsevier Science Ire land Ltd. All rights reserved.