Ascorbic acid improves impaired venous and arterial endothelium dependent dilation in smokers

• 来源期刊: 中国药理学报（英文版）
• 关键词: ascorbic acid vasodilation vascular endothelium arterioles venules dorsal hand vein flow-mediated dilation
• 年，卷（期）: 2005,（4）
• 页码范围: 447-452
• 页数: 6页
• 语种: 英文

摘要

Aim: To compare the acute effects of ascorbic acid on vasodilation of veins and arteries in vivo. Methods: Twenty-six healthy non-smokers and 23 healthy moderate smokers were recruited in this study. The dorsal hand vein compliance technique and flow-mediated dilation were used. Dose-response curves to bradykinin and sodium nitroprusside were constructed to test the endothelium-dependent and -independent relaxation before and after acute infusion of ascorbic acid. Results: Smokers had an impaired venodilation with bradykinin compared with non-smokers (68.3%±13.2% vs 93.7%±20.1%, respectively; P＜0.05). Ascorbic acid administration in the dorsal hand vein significantly increased the venodilation with bradykinin in smokers (68.3%± 13.2% vs 89.5%±6.3% before and after infusion, respectively; P＜0.05) but not in non-smokers (93.7%±20.1% vs 86.4%±12.4% before and after infusion, respectively). Similarly, the arterial response in smokers had an impaired endothelium-dependent dilation compared with that in non-smokers (8.8%±2.7% vs 15.2%±2.3%, respectively; P＜0.05) and ascorbic acid restored this response in smokers (8.8%±2.7% vs 18.7%±6.5% before and after infusion, respectively; P＜0.05), but no difference was seen in non-smokers (15.2%±2.3% vs 14.0%±4.4% before and after infusion, respectively). The endothelium-independent dilation did not differ in both the groups studied. No important hemodynamic change was detected using the Portapress device. Conclusion: Smokers had impaired endothelium-dependent vasodilation responsiveness in both arterial and venous systems. Ascorbic acid restores this responsiveness in smokers.