Corneal alkali burns are potentially blinding injuries. Alkali induces oxidative stress in corneas followed by excessive corneal inflammation, neovascularization, and untransparent scar formation. Molecular hydrogen (H2), a potent reactive oxygen species (ROS) scavenger, suppresses oxidative stress and enables corneal healing when applied on the corneal surface. The purpose of this study was to examine whether the H2 pretreatment of healthy corneas evokes a protective effect against corneal alkali-induced oxidative stress. Rabbit eyes were pretreated with a H2 solution or buffer solution, by drops onto the ocular surface, and the corneas were then burned with 0.25 M NaOH. The results obtained with immunohistochemistry and pachymetry showed that in the corneas of H2-pretreated eyes, slight oxidative stress appeared followed by an increased expression of antioxidant enzymes. When these corneas were postburned with alkali, the alkali-induced oxidative stress was suppressed. This was in contrast to postburned buffer-pretreated corneas, where the oxidative stress was strong. These corneas healed with scar formation and neovascularization, whereas corneas of H2-pretreated eyes healed with restoration of transparency in the majority of cases. Corneal neovascularization was strongly suppressed. Our results suggest that the corneal alkali-induced oxidative stress was reduced via the increased antioxidant capacity of corneal cells against reactive oxygen species (ROS). It is further suggested that the ability of H2 to induce the increase in antioxidant cell capacity is important for eye protection against various diseases or external influences associated with ROS production.

• MeSH
• alkálie toxicita   MeSH
• antioxidancia metabolismus   MeSH
• chemické popálení farmakoterapie   metabolismus   patologie   MeSH
• epitelové buňky účinky léků   metabolismus   patologie   MeSH
• hojení ran účinky léků   MeSH
• králíci MeSH
• modely nemocí na zvířatech MeSH
• neovaskularizace rohovky prevence a kontrola   MeSH
• oxidační stres účinky léků   MeSH
• popálení oka chemicky indukované   farmakoterapie   metabolismus   patologie   MeSH
• reaktivní formy kyslíku metabolismus   MeSH
• rohovka krevní zásobení   účinky léků   metabolismus   patologie   MeSH
• vodík farmakologie   terapeutické užití   MeSH
• zvířata MeSH
• Check Tag
• králíci MeSH
• ženské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• publikace stažené z tisku MeSH
• Názvy látek
• alkálie MeSH
• antioxidancia MeSH
• reaktivní formy kyslíku MeSH
• vodík MeSH

The aim of this study is to examine whether molecular hydrogen (H2) is able to reduce oxidative stress after corneal damage induced by UVB irradiation. We previously found that UVB irradiation of the cornea caused the imbalance between the antioxidant and prooxidant enzymes in the corneal epithelium, followed by the imbalance between metalloproteinases and their physiological inhibitors (imbalances in favour of prooxidants and metalloproteinases) contributing to oxidative stress and development of the intracorneal inflammation. Here we investigate the effect of H2 dissolved in PBS in the concentration 0.5 ppm wt/vol, applied on rabbit corneas during UVB irradiation and healing (UVB doses 1.01 J/cm2 once daily for four days). Some irradiated corneas remained untreated or buffer treated. In these corneas the oxidative stress appeared, followed by the excessive inflammation. Malondiladehyde and peroxynitrite expressions were present. The corneas healed with scar formation and neovascularization. In contrast, in H2 treated irradiated corneas oxidative stress was suppressed and malondiladehyde and peroxynitrite expressions were absent. The corneas healed with the restoration of transparency. The study provides the first evidence of the role of H2 in prevention of oxidative and nitrosative stress in UVB irradiated corneas, which may represent a novel prophylactic approach to corneal photodamage.

• MeSH
• králíci MeSH
• kyselina peroxydusitá metabolismus   MeSH
• malondialdehyd metabolismus   MeSH
• oxidační stres účinky léků   účinky záření   MeSH
• poranění rohovky farmakoterapie   metabolismus   MeSH
• reaktivní formy kyslíku metabolismus   MeSH
• rohovka účinky léků   metabolismus   účinky záření   MeSH
• ultrafialové záření * MeSH
• vodík terapeutické užití   MeSH
• zvířata MeSH
• Check Tag
• králíci MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• publikace stažené z tisku MeSH
• Názvy látek
• kyselina peroxydusitá MeSH
• malondialdehyd MeSH
• reaktivní formy kyslíku MeSH
• vodík MeSH

The aim of this study was to examine the effect of molecular hydrogen (H2) on the healing of alkali-injured cornea. The effects of the solution of H2 in phosphate buffered saline (PBS) or PBS alone topically applied on the alkali-injured rabbit cornea with 0.25 M NaOH were investigated using immunohistochemical and biochemical methods. Central corneal thickness taken as an index of corneal hydration was measured with an ultrasonic pachymeter. Results show that irrigation of the damaged eyes with H2 solution immediately after the injury and then within next five days renewed corneal transparency lost after the injury and reduced corneal hydration increased after the injury to physiological levels within ten days after the injury. In contrast, in injured corneas treated with PBS, the transparency of damaged corneas remained lost and corneal hydration elevated. Later results-on day 20 after the injury-showed that in alkali-injured corneas treated with H2 solution the expression of proinflammatory cytokines, peroxynitrite, detected by nitrotyrosine residues (NT), and malondialdehyde (MDA) expressions were very low or absent compared to PBS treated injured corneas, where NT and MDA expressions were present. In conclusion, H2 solution favorably influenced corneal healing after alkali injury via suppression of oxidative stress.

• MeSH
• aktiny metabolismus   MeSH
• cytokiny metabolismus   MeSH
• exprese genu účinky léků   MeSH
• hydroxid sodný toxicita   MeSH
• imunohistochemie MeSH
• interleukin-1beta genetika   metabolismus   MeSH
• keratin-12 metabolismus   MeSH
• keratin-3 metabolismus   MeSH
• králíci MeSH
• kyselina peroxydusitá metabolismus   MeSH
• malondialdehyd metabolismus   MeSH
• modely nemocí na zvířatech MeSH
• oxidační stres účinky léků   MeSH
• poranění rohovky etiologie   metabolismus   patologie   MeSH
• rohovka metabolismus   patologie   MeSH
• vaskulární endoteliální růstový faktor A genetika   metabolismus   MeSH
• vodík farmakologie   MeSH
• zvířata MeSH
• Check Tag
• králíci MeSH
• ženské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• publikace stažené z tisku MeSH
• Názvy látek
• aktiny MeSH
• cytokiny MeSH
• hydroxid sodný MeSH
• interleukin-1beta MeSH
• keratin-12 MeSH
• keratin-3 MeSH
• kyselina peroxydusitá MeSH
• malondialdehyd MeSH
• vaskulární endoteliální růstový faktor A MeSH
• vodík MeSH