氨基胍对D-半乳糖致大鼠眼晶状体损伤的影响及其机制

Effects of aminoguanidine intervention on lens cell damage induced by D-galactose in rat eyes

目的:探讨D-半乳糖致大鼠眼晶体损伤及氨基胍的干预作用及其机制。方法:D-半乳糖(400mg.kg-1)腹腔注射给药,2周后模型大鼠给予氨基胍(AG)高剂量(150mg.kg-1)和低剂量(75mg.kg-1)处理至第14周。处理动物并取血测定红细胞醛糖还原酶(AR)活性、糖化血红蛋白、血清果糖胺(FRA)和晚期糖基化终末产物(AGEs)含量;取眼晶状体测定AR、GR、SOD和SDH活性,测定AGEs、GSH、MDA含量和乳酸脱氢酶(LDH)漏出量,流式细胞术检测晶状体上皮细胞凋亡情况,透射电镜观察晶状体上皮细胞超微结构的变化。结果:D-半乳糖处理动物14周后,体内糖化血红蛋白、血清果糖胺、AGEs水平和AR活性明显升高,并伴有眼晶状体AGEs含量和AR活性的增加,抗氧化酶活性降低,氧化产物增加,晶状体上皮细胞出现凋亡及细胞核和线粒体结构的损伤。氨基胍处理12周后,明显降低动物体内红细胞和晶状体AR活性(P<0.01),降低糖化血红蛋白、血清果糖胺和AGEs含量,降低晶状体AGEs、MDA含量(P<0.01)和LDH释放量(P<0.05),提高GR、SDH和SOD活性(P<0.05或P<0.01),并降低晶状体上皮细胞凋亡率(P<0.05或P<0.01),减少细胞核和线粒体的损伤程度。结论:氨基胍对D-半乳糖致大鼠全身和眼晶状体糖基化和氧化应激性损伤具有抑制作用,并减缓其对眼晶状体上皮细胞核和线粒体结构的损伤,抑制细胞凋亡的发生。

AIM ： To investigate the effects of aminoguanidine intervention on lens cell damage induced by D - galactose in rat eyes and its mechanism of action. METHODS： D -galactose （400 mg/kg） was injected into rats intraperitoneally for 14 weeks to induce the animal model of glycosylation and lens cell damage. Aminoguanidine （75 mg/kg, 150 mg/kg） were administered for 12 weeks by intragastrie administration beginning at 3rd week. All animals were killed and blood samples were taken to measure the activity of aldose reduetase, the level of fructosamine, the amounts of glycohaemoglobin and advanced glycation end -products. The lenses of eyes were taken to detect the activities of AR, GR, SOD and SDH. The amounts of AGEs, GSH, MDA or outleakage of LDH were measured, respectively. The uhrastrueture and apeptosis of lens epithelial cells were examined by transmission electron microscope and flow cytometry, respectively. RESULTS： Animals were treated with D -galactose for 14 weeks, the serum level of fructosamine, the amounts of glyeohaemoglobin and AGEs, and activity of AR were significantly increased. The amount of AGEs and activity of AR in lens were increased, the activity of antioxidase was decreased and oxidative product was increased. The apoptosis, the damages of mitochondria and cell nucleus in lens cells were observed. After treated with aminoguanidine for 12 weeks, the activity of AR and the level of fructosamine in serum, and the amounts of glyeohaemoglobin and AGEs were significantly decreased （P 〈 0. 01 ）. The outleakage of LDH and amount of MDA were also decreased （P 〈0. 05, P 〈 0. 01 ）, the activities of GR, SDH and SOD were increased （P 〈0. 05, P 〈0. 01 ）. The apoptotic rate of lens cells was reduced （P 〈0. 05, P 〈0. 01 ）. The morphology of mitochondria and cell nucleus were improved. CONCLUSION： D - galactose induces the damage of cell nucleus, the mitochondria and apoptosis in lens cells by glycosylation and oxidative stress. Aminoguanidine may supply the protective action through inhibiting the glycosylation and oxidative stress.