小中大3.3 关于内源性氢气的作用人类和高等动物体内也存在一定水平的氢气,目前认为,这些氢气不是机体自身组织产生,而是来自大肠细菌代谢被人体吸收。有人曾测定正常小鼠体内不同器官氢气水平,结果发现,小鼠大肠、脾、肝、胃黏膜等部位氢气水平非常高,如在肝脏可达到42 µmol/L,大肠和脾的水平更高[26]。十分巧合地是,采用PC12细胞氧化损伤模型研究表明,只要培养基内氢气浓度达到25 µmol/L(水中最大可溶解600 µmol/L,脂肪最大可溶解1 200 µmol/L),就可显示出明显的抗氧化作用[5]。这说明,在正常小鼠肝脏等腹腔器官,内源性氢气已经明显超过抗氧化所需要的水平。正常人终末呼吸气氢水平大约(5~10)×10-6(V/V),乳糖不耐受和菌群紊乱等疾病患者呼吸气中氢水平可明显增加到(100~200)×10-6(V/V),临床上可通过检测呼吸气中的氢水平用来诊断上述疾病[27]。氢气在体抗氧化作用的发现,提示我们需要重新评价人体内氢的生物学效应[8]。
总之,氢气具有选择性抗氧化作用的发现具有十分重要的意义,不仅会引起基础和临床医学领域的很大兴趣,而且可能对人类疾病的防治产生深远影响。但由于该领域的研究深度和广度有限,目前尚难以进行更加全面清晰描述和准确推测。我们将不断关注和总结该领域的发展,也希望引起更多人对氢分子医学的关注。
参考文献
1. Buxton G V,Greenstock C L,Helman W P,Ross A B.Critical-review of rate constants for reactions of hydrated electrons, hydrogen atoms and hydroxyl radicals (·OH/·O—) in aqueous solution[J].J Phys Chem Ref Data,1988,17:513-886.
2. Kayar S R,Axley M J,Homer L D,Harabin A L.Hydrogen gas is not oxidized by mammalian tissues under hyperbaric conditions[J].Undersea Hyperb Med,1994,21:265-275.
3. Dole M,Wilson F R,Fife W P.Hyperbaric hydrogen therapy:a possible treatment for cancer[J]. Science, 1975, 190:152-154.
4. Gharib B,Hanna S,Abdallahi O M,Lepidi H,Gardette B,De Reggi M.Anti-inflammatory properties of molecular hydrogen: investigation on parasite-induced liver inflammation[J].C R Acad Sci III,2001,324:719- 724.
5. Ohsawa I,Ishikawa M,Takahashi K,Watanabe M,Nishimaki K,Yamagata K,et al.Hydrogen acts as a therapeutic antioxidant by selectively reducing cytotoxic oxygen radicals[J].Nat Med,2007,13:688-694.
6. Wood K C,Gladwin M T.The hydrogen highway to reperfusion therapy[J].Nat Med,2007,13:673-674.
7. Singhal A B,Lo E H.Advances in emerging nondrug therapies for acute stroke 2007[J].Stroke,2008,39:289- 291.
8. Sun X J, Zhang J H.Hydrogen--an endogenous antioxidant in the body[J].Acad J Sec Mil Med Univ,2008,29: 233-235.
9. Fukuda K I,Asoh S,Ishikawa M,Yamamoto Y,Ohsawa I,Ohta S.Inhalation of hydrogen gas suppresses hepatic injury caused by ischemia/reperfusion through reducing oxidative stress[J].Biochem Biophys Res Commun, 2007,361:670-674.
10. Hayashida K,Sano M,Ohsawa I,Shinmura K,Tamaki K,Kimura K,et al.Inhalation of hydrogen gas reduces infarct size in the rat model of myocardial ischemia-reperfusion injury[J].Biochem Biophys Res Commun, 2008,373:30-35.
11. Ohsawa I,Nishimaki K,Yamagata K,Ishikawa M,Ohta S.Consumption of hydrogen water prevents atherosclerosis in apolipoprotein E knockout mice[J].Biochem Biophys Res Commun,2008,377:1195-1198.
12. Kajiyama S,Hasegawa G,Asano M,Hosoda H,Fukui M,Nakamura N,et al.Supplementation of hydrogen-rich water improves lipid and glucose metabolism in patients with type 2 diabetes or impaired glucose tolerance[J]. Nutr Res,2008,28:137-143.
13. Sato Y,Kajiyama S,Amano A,Kondo Y,Sasaki T,Handa S,et al.Hydrogen-rich pure water prevents superoxide formation in brain slices of vitamin C-depleted SMP30/GNL knockout mice[J].Biochem Biophys Res Commun,2008,375:346-350.
14. Nagata K,Nakashima-Kamimura N,Mikami T,Ohsawa I,Ohta S.Consumption of molecular hydrogen prevents the stress-induced impairments in hippocampus-dependent learning tasks during chronic physical restraint in mice[J].Neuropsychopharmacology,2009,34:501-508.
15. Nakashima-Kamimura N,Mori T,Ohsawa I,Asoh S,Ohta S.Molecular hydrogen alleviates nephrotoxicity induced by an anti-cancer drug cisplatin without compromising anti-tumor activity in mice[J].Cancer Chemother Pharmacol,2009 Jan 16. [Epub ahead of print]
16. Fu Y,Ito M,Fujita Y,Ito M,Ichihara M,Masuda A,et al.Molecular hydrogen is protective against 6-hydroxydopamine -induced nigrostriatal degeneration in a rat model of Parkinson’s disease[J]. Neurosci Lett,2009,453:81-85.
17. Buchholz B M,Kaczorowski D J,Sugimoto R,Yang R,Wang Y,Billiar T R,et al.Hydrogen inhalation ameliorates oxidative stress in transplantation induced intestinal graft injury[J].Am J Transplant,2008,8: 2015-2024.
18. Cai J,Kang Z,Liu W W,Luo X,Qiang S,Zhang J H,et al.Hydrogen therapy reduces apoptosis in neonatal hypoxia-ischemia rat model[J].Neurosci Lett,2008,441:167-172.
19. Cai J,Kang Z,Liu K,Liu W,Li R,Zhang J H,et al.Neuroprotective effects of hydrogen saline in neonatal hypoxia-ischemia rat model[J].Brain Res,2009,1256:129-137.
20. Mao Y F,Zheng X F,Cai J M,You X M,Deng X M,Zhang J H,et al. Hydrogen-rich saline reduces lung injury induced by intestinal ischemia/reperfusion in rats[J].Biochem Biophys Res Commun,2009,381:602-605.
21. Zheng X,Mao Y,Cai J,Li Y,Liu W,Sun P,et al.Hydrogen-rich saline protects against intestinal ischemia/ reperfusion injury in rats[J].Free Radic Res,2009,43:478-484.
22. Abraini J H,Gardette-Chauffour M C,Martinez E,Rostain J C,Lemaire C.Psychophysiological reactions in humans during an open sea dive to 500 m with a hydrogen-helium-oxygen mixture[J]. J Appl Physiol,1994,76: 1113-1138.
23. Chan P H.Role of oxidants in ischemic brain damage[J].Stroke,1996,27:1124-1129.
24. Liu S,Liu M,Peterson S,Miyake M,Vallyathan V,Liu K J.Hydroxyl radical formation is greater in striatal core than in penumbra in a rat model of ischemic stroke[J].J Neurosci Res,2003,71:882-888.
25. Nanetti L,Taffi R,Vignini A,Moroni C, Raffaelli F,Bacchetti T,Silvestrini M,et al.Reactive oxygen species plasmatic levels in ischemic stroke[J].Mol Cell Biochem,2007,303:19-25.
26. Olson J W,Maier R J.Molecular hydrogen as an energy source for Helicobacter pylori[J].Science,2002,298: 1788-1790.
27. Simren M,Stotzer P O.Use and abuse of hydrogen breath tests[J].Gut,2006,55:297-303.