Bilgihan Ayşe, Bilgihan Kamil, Yis Ozgür, Yis Nilgün Safak, Hasanreisoglu Berati
Department of Biochemistry, Gazi University Faculty of Medicine, Ankara, Turkey.
Free Radic Res. 2003 Apr;37(4):399-403. doi: 10.1080/1071576031000064711.
Glutathione related enzymes are involved in the metabolism and detoxification of cytotoxic and carcinogenic compounds as well as reactive oxygen species. Excimer laser is a very useful tool for the treatment of refractive errors and removing superficial corneal opacities. Previous studies have shown that excimer laser may initiate free radical formation in the cornea. In the present study, we evaluated the effect of excimer laser keratectomy on corneal glutathione-related enzyme activities in rabbits. Animals were divided into five groups, and all groups were compared with the controls (group 1), after epithelial scraping (group 2), transepithelial photorefractive keratectomy (PRK) (group 3), traditional PRK (group 4) and deep traditional PRK (group 5). Corneal glutathione peroxidase (GPx), glutathione S-transferase (GST) and glutathione reductase (GR) activities were measured after 24h. Corneal GPx and GR activities significantly decreased only in group 5 (p < 0.05) but GST activities significantly decreased in all groups when compared with the control group (p < 0.05). In conclusion, excimer laser inhibits the glutathione dependent defense system in the cornea, this effect becomes more prominent after high doses of excimer laser energy and antioxidants may be useful to reduce free radical mediated complications.
谷胱甘肽相关酶参与细胞毒性和致癌化合物以及活性氧的代谢和解毒过程。准分子激光是治疗屈光不正和去除浅层角膜混浊的一种非常有用的工具。先前的研究表明，准分子激光可能会在角膜中引发自由基的形成。在本研究中，我们评估了准分子激光角膜切削术对兔角膜谷胱甘肽相关酶活性的影响。将动物分为五组，并将所有组与对照组（第1组）、上皮刮除术后（第2组）、经上皮光屈光性角膜切削术（PRK）（第3组）、传统PRK（第4组）和深层传统PRK（第5组）进行比较。24小时后测量角膜谷胱甘肽过氧化物酶（GPx）、谷胱甘肽S-转移酶（GST）和谷胱甘肽还原酶（GR）的活性。与对照组相比，仅第5组角膜GPx和GR活性显著降低（p<0.05），但所有组的GST活性均显著降低（p<0.05）。总之，准分子激光抑制角膜中依赖谷胱甘肽的防御系统，高剂量准分子激光能量后这种作用更为明显；抗氧化剂可能有助于减少自由基介导的并发症。
