大鼠角膜碱、酸、热烧伤后房水中TGF-β2的变化研究

目的:通过检测角膜烧伤后前房水中TGF-β2含量的变化,探讨在眼部内环境下TGF-β2与角膜烧伤之间的关系,为角膜烧伤治疗提供依据。方法:制备Wistar大鼠角膜碱、酸、热中度烧伤动物模型,分别于伤后4,8h;1,3,5,7,14,28,49d处死。采集房水:用20g/LBSA包被的毛细管于角膜缘处刺入角膜,吸取房水至20g/LBSA包被的离心管中,-70℃保存。标准品和样品进行酸激活处理。使用ELISA方法检测角膜烧伤后前房水中TGF-β2的水平。结果:大鼠角膜碱烧伤后4hTGF-β2的水平呈现一过性升高,然后下降,3d时TGF-β2含量再次升高,7d时达高峰,持续至7wk时降至正常。大鼠角膜酸烧伤后4hTGF-β2的水平呈现一过性升高,然后下降,低于正常对照组,两者差异显著。7d时房水中TGF-β2升至正常,然后一直保持低平状态。49d时我们检测房水中TGF-β2水平仍低于正常。大鼠角膜热烧伤后4hTGF-β2的水平呈现一过性升高,1d时降至最低,3d时开始增长,直到7d时我们检测仍高于正常,然后缓慢下降。结论:角膜烧伤后前房水中TGF-β2的含量发生变化,致伤原因不同,其变化方式不同。角膜碱烧伤和热烧伤后于7d时出现TGF-β2高峰,说明此时角膜处于免疫功能抑制状态,这对于维持角膜前房的免疫赦免状态非常重要,证明此时机体发挥了自我保护功能,避免产生过度的病理反应。角膜酸烧伤后TGF-β2水平始终低平,其原因尚有待于进一步研究。

Expression of TGF-β2 in rat aqueous humor following corneal alkali burns,acid burns and thermal burns

AIM: To study the relationship between TGF-β2 and ocular burns by detecting the levels of TGF-β2 in rat aqueous humor following corneal alkali burns, acid burns and thermal burns and to provide experimental clues. ·METHODS: The models of alkali burns, acid burns and thermal burns in Wistar rats were established and the animals were sacrificed at 4, 8 hours, 1, 3 day, 1, 2, 4 and 7 weeks after burn. Aqueous humor was obtained by the anterior chamber paracentesis and frozen at -70℃. 1mol/L HCl was added to the samples to acid activation. The levels of TGF-β2 were assessed with a specific-capture ELISA kit. ·RESULTS: The levels of TGF-β2 in rat aqueous humor following corneal alkali burns increased at 4 hours after injury and decreased quickly. The second increase was appeared at 3 days, reached to the peak at 1 week and came back to the normal at 7 weeks. The levels of TGF-β2 in rat aqueous humor following corneal acid burns increased at 4 hours after injury and decreased quickly. There was significant difference compared to the control. The levels of TGF-β2 increased to the normal at 1 week and lasted low expression as far as 7 weeks. The levels of TGF-β2 in rat aqueous humor following corneal thermal burns increased at 4 hours after injury and decreased quickly to the lowest expression at 1 day. We observed the second increase at 3 days and it lasted higher expression for long time. ·CONCLUSION: The levels of TGF-β2 in rat aqueous humor changes following ocular burns. There is difference among different burns. The levels of TGF-β2’s peak appears respectively at 1 week following alkali burns and thermal burns show the cornea be in immunosup-pressive state this time and it is very important to maintain the immune privileged status of the anterior chamber. It is proved that the self-safeguard of the body avoids excessive pathological reaction. The reason of low levels of TGF-β2 following acid burns needs more study.