ANALYSIS OF PLATELET AND WHITE BLOOD CELL MEMBRANE RECEPTOR. (PREVENTION AND TREATMENT OF PULMONARY VASCULAR INJURY.)

研究了四氧嘧啶诱导的糖尿病兔主动脉内皮细胞对氧化应激的防御系统，并评价了胰岛素对其抗氧化活性的影响。10只糖尿病兔、18只胰岛素治疗的糖尿病兔和10只年龄匹配的对照组在糖尿病17d后制备内皮细胞。这些细胞被用来估计谷胱甘肽(GSH)水平及其相关的酶活性。将糖尿病兔血管内皮细胞的抗氧化活性与对照组进行比较。糖尿病兔血中GSH浓度降低(1.6×0.2nmol/mg蛋白[Mean*SD]nu 3.7×0.6nmoL/mg蛋白)。铜的活性降低。过氧化氢酶(7.6U×2.1U/mg蛋白vs12.3×3.2U/mg蛋白)；谷胱甘肽过氧化物酶(134.0×27.0mU/mg蛋白vs179.1×26.2mU/mg蛋白)。谷胱甘肽相关酶SU-…的活性糖尿病兔血管内皮细胞中谷胱甘肽S转移酶或还原型谷胱甘肽还原酶未见明显变化。当糖尿病兔接受胰岛素(1-2U/kg/d)治疗时，这些抗氧化活性大部分被阻止。在糖尿病患者的肝脏和肾脏中也检测到了这些抗氧化活性。在糖尿病肝脏中观察到类似的细胞防御活性的降低和胰岛素对活性降低的预防，而肾脏中的这些抗氧化酶活性对糖尿病条件具有抵抗力。糖尿病大鼠肝脏中SGSH合成酶--γ-谷氨酰半胱氨酸合成酶活性降低，这可能是GSH浓度降低的原因之一。这些结果表明，与在肝脏中观察到的那样，糖尿病兔内皮细胞中的GSH及其相关酶活性受到损害，这些损害可以通过胰岛素治疗来预防。抗氧化活性的降低可能在糖尿病相关的病理谱系中具有重要意义。较少

The defense system of aortic endothelial cells against oxidative stress was studied in alloxan-induced diabetic rabbits,and the effect of insulin on the antioxidant activities was estimated. Endothelial cells were prepared from 10 diabetic rabbits, 18 diabetic rabbits treated with insulin, and 10 age-matched controls after 17 days of diabetes. These cells were used for the estimation of glutathione (GSH) levels and its related enzyme activities. The antioxidant activities in these endothelial cells from diabetic rabbits were compared with those from control subjects. The concentration of GSH decreased in diabetic rabbits (1.6*0.2 nmol/mg protein [mean*SD] nu 3.7*0.6nmol/mg protein). Decreases in the activities of Cu. Zn-superoxide dismutase(Cu,Zn-SOD)(62.7*11.0U/mg protein nu 172.9*20.2U/mg protein),catalase(7.6*2.1U/mg protein v 12.3*3.2 U/mg protein), and GSH peroxidase (134.0*27.0 mU/mg protein v 179.1*26.2 mU/mg protein) were observed. The activities of other GSH-related enzymes su … More ch as GSH S-transferase or GSH reductase did not change in endothelial cells from diabetic rabbits. Most of these antioxidant activities were prevented when diabetic rabbits were treated with insulin (1 to 2 U/kg/d). These antioxidant activities were also determined in the diabetic liver and kidney. Similar decreases in the cellular defense activities and prevention of the decrease in activities by insulin were observed in the diabetic liver, while these antioxidant enzyme activities in the kidney were resistant to diabetic conditions. The activity of a SGSH-synthesizing enzyme, gamma-glutamylcysteine synthetase,decreased in diabetic liver,which may account for the decrease in the concentration of GSH. These results indicate that GSH and its related enzyme activities are impaired in endothelial cells from diabetic rabbits as observed in the liver,and that these impairments are prevented by treatment with insulin. The decrease in antioxidant activity may have significance in the spectrum of pathology associated with diabetes mellitus. Less