Glavas Duska, Bakovic Darija, Obad Ante, Palada Ivan, Breskovic Toni, Valic Zoran, Brubakk Alf O, Dujic Zeljko
Department of Internal Medicine, University Hospital Split, Split, Croatia.
Clin Physiol Funct Imaging. 2009 Apr;29(2):100-7. doi: 10.1111/j.1475-097X.2008.00845.x. Epub 2008 Dec 4.
Self-contained underwater breathing apparatus diving reduces cardiovascular function and increases pulmonary artery pressure (PAP) up to 3 days after a single dive. Acute antioxidants partially attenuated arterial endothelial dysfunction, whereas cardiac and PA functions were unaffected. We tested the hypothesis that acute tetrahydobiopterin (BH(4)), as a cofactor of endothelial nitric oxide (NO) synthase, reduces bubble grade (BG) and attenuates alteration in cardiovascular function after diving because of increased NO bioavailability.
Mean PAP (mPAP), PA acceleration time and right ventricle ejection time, left ventricle ejection fraction (LV-EF) and BG were measured after oral placebo (P), vitamin C (C) or a combination of vitamin C and BH(4) (BH(4)) in a randomized, placebo controlled trial before and after field dive to 30 m of sea water for 30 min bottom time.
Eight recreational divers performed three dives with a 3-days period between them. Regarding the primary hypothesis, no difference was observed between post-dive changes in BG (2.1 +/- 2.2 bubbles cm(-2) for P, 3.4 +/- 3.9 for C and 3.6 +/- 2.1 for BH(4)), mPAP (25.6 +/- 6.5 mmHg for P, 25.9 +/- 8.6 for C and 22.6 +/- 3.5 for BH(4)) and LV-EF (62.6 +/- 4.6% for P, 61.4 +/- 3.9 for C and 61.6 +/- 3.7 for BH(4)) with all three conditions.
This suggests that co-administration of BH(4) and vitamin C does not improve heart and pulmonary artery function after diving.
自给式水下呼吸器潜水会降低心血管功能，并在单次潜水后长达3天内使肺动脉压力（PAP）升高。急性抗氧化剂可部分减轻动脉内皮功能障碍，而心脏和肺动脉功能则未受影响。我们检验了以下假设：作为内皮型一氧化氮（NO）合酶的辅助因子，急性四氢生物蝶呤（BH(4)）可降低气泡等级（BG），并因增加NO生物利用度而减轻潜水后心血管功能的改变。
在一项随机、安慰剂对照试验中，对8名休闲潜水员在实地潜水至30米海水深度并在水底停留30分钟之前和之后，口服安慰剂（P）、维生素C（C）或维生素C与BH(4)的组合（BH(4)）后，测量平均PAP（mPAP）、肺动脉加速时间和右心室射血时间、左心室射血分数（LV-EF）以及BG。
8名休闲潜水员进行了三次潜水，每次潜水间隔3天。关于主要假设，在所有三种情况下，潜水后BG（P组为2.1±2.2个气泡/cm²，C组为3.4±3.9，BH(4)组为3.6±2.1）、mPAP（P组为25.6±6.5 mmHg，C组为25.9±8.6，BH(4)组为22.6±3.5）和LV-EF（P组为62.6±4.6%，C组为61.4±3.9，BH(4)组为61.6±3.7）的变化之间未观察到差异。
这表明潜水后联合使用BH(4)和维生素C并不能改善心脏和肺动脉功能。
