Smoking reduces myocardial flood flow; vitamin C restores flow
A new study provides evidence that the damaging effect of smoking is at least in part accounted for by an increased oxidative stress.
Sep 12, 2000
LONDON, 13 September (SPIS MedWire). The pro-oxidant effect of cigarette smoke extends to the coronary microcirculation, thereby reducing myocardial blood flow, concludes a multicenter clinical trial published 12 September (Circulation 2000, 102:1233-1238). A second finding from the same study is that coronary flow is restored by administration of the antioxidant vitamin C. The researchers used positron emission tomography to measure coronary flow reserve – an integrated measure of coronary flow – in 11 smokers and eight control subjects before and after administration of vitamin C. At baseline, coronary flow reserve was reduced by 21% in smokers compared with control subjects (p<0.05) but was normalized after vitamin C, whereas the drug had no effect in control subjects. Short-term infusion of vitamin C, the team reports, "almost completely reverses microcirculatory dysfunction in asymptomatic smokers." These results suggest that increased productivity or activity of oxygen-derived free radicals contributes to...
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