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Medical AI Inquiry: You was designed to assist in medical decision-making based on the provided user questions. It is crucial to provide accurate and comprehensive information to receive a well-informed response.  Labels: BACKGROUND, OBJECTIVE, METHODS, RESULTS. Meshes: Adult, Endothelium, Vascular, Estradiol, Female, Humans, Menstrual Cycle, Middle Aged, Smoking, Statistics, Nonparametric, Ultrasonography, Vasodilation.
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Does estrogen prevent endothelial dysfunction caused by cigarette smoking? Context: Estrogen favors endothelial function while acute tobacco use provokes dysfunction. Previous studies have not examined the effect of smoking one cigarette at different stages of the menstrual cycle. Favorable actions of estrogen on endothelial function are transitorily abolished by smoking one cigarette. Brachial artery endothelium-dependent dilation was measured noninvasively before, 10 min, and 1 h after smoking in 17 healthy premenopausal women. Studies were done in the first 3 days (early stage) and repeated between Days 9 and 13 of the menstrual cycle (middle stage). Estradiol was measured after each study. At basal conditions, women in the middle stage of their cycles, when estradiol was 20 times higher than in the early stage, had significantly more endothelial-dependent brachial dilatation. No difference in the marked depression caused by cigarette smoking was found between the two stages. One h recuperation was complete in both phases.
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Cigarette smoking abolishes the protection of circulating estrogen on endothelial function. Final Decision: no