牛磺酸营养干预下缺氧大鼠视网膜中葡萄糖转运蛋白1的表达

目的 观察高原缺氧条件下大鼠视网膜中葡萄糖转运蛋白1(GLUT-1)的变化,探讨牛磺酸对视网膜缺氧适应的影响.方法 96只SD大鼠随机分为6组,对照组(C)、牛磺酸组(T)、4 500 m缺氧组(45H)、4 500 m缺氧 牛磺酸组(45HT)、5 500 m缺氧组(55H)和5 500 m缺氧 牛磺酸组(55HT),分别以基础饲料和添加了2.4%牛磺酸的饲料喂养1周,营养干预后C组、T组继续在平原饲养,45H组、45HT组和55H组、55HT组放入低压氧舱分别模拟4 500 m和5 500 m高度的高原缺氧条件.在处理0、1、2、3 d后取视网膜,提取总RNA和总蛋白,应用RT-PCR和Western blot方法检测视网膜GLUT-1 mRNA和蛋白表达.结果 缺氧第1天视网膜中GLUT-1 mRNA与蛋白的表达显著降低(P＜0.05).缺氧第2天 mRNA与蛋白的表达开始回升,第3天 mRNA的表达恢复正常水平,蛋白的表达高于对照,牛磺酸处理后表达量均比对应的缺氧组高.结论 高原缺氧条件下,牛磺酸能通过上调GLUT-1的表达促进视网膜缺氧适应性调节机制的建立.

Expression of glucose transporter type 1 in rat retina induced by hypoxia and taurine

Objective To explore the effect of taurine on glucose transporter type 1(GLUT-1)in rat retina and investigate the protection mechanism of taurine to hypoxia. Methods Ninety-six adult Sprague Dawley rats were divided into 6 groups randomly. The rats in control group (C) , 4 500-meter hypoxia group (45H)and 5 500-meter hypoxia group (55H) were fed with regular forage, while the rats in taurine group (T) , 4 500-meter hypoxia combining with taurine group (45HT)and 5 500-meter hypoxia with taurine group (55HT) were supplemented with forage containing 2.4% taurine for one week. Then rats of 45H, 45HT, 55H, and 55HT groups were put into low-pressure chamber in which air condition at 4 500-meter and 5 500-meter altitude was simulated respectively. On day 0, 1, 2, 3 after hypoxia, retinas were taken out to extract total RNA and protein. Expression of GLUT-1 in retina was determined by RT-PCR and Western blotting. Results The expression of GLUT-1 mRNA and protein in retina decreased on day 1 after hypoxia,(P<0.05), began to rise on day 2, and mRNA returned to control level and protein expression overpassed control level on day 3. Taurine up-regulated the expression as compared with hypoxia groups. Conclusion Taurine will promote the adaptability adjustment of hypoxic retina through up-regulating GLUT-1 that keeps normal visual function in high-altitude hypoxia.