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家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。从10只糖尿病兔、18只胰岛素治疗的糖尿病兔和10只年龄匹配的糖尿病兔中制备内皮细胞。这些细胞用于估计谷胱甘肽（GSH）水平及其相关酶活性。将糖尿病家兔内皮细胞的抗氧化活性与正常家兔进行比较。糖尿病家兔GSH浓度降低（1.6*0.2 nmol/mg蛋白[mean*SD] = 3.7*0.6nmol/mg蛋白）。Cu的活度降低。观察到锌超氧化物歧化酶（Cu,Zn-SOD）（62.7*11.0U/mg蛋白vs 172.9*20.2U/mg蛋白）、过氧化氢酶（7.6*2.1U/mg蛋白vs 12.3*3.2 U/mg蛋白）和谷胱甘肽过氧化物酶（134.0*27.0 mU/mg蛋白vs 179.1*26.2 mU/mg蛋白）。其他与谷胱甘肽相关的酶，如谷胱甘肽s -转移酶和谷胱甘肽还原酶的活性在糖尿病家兔内皮细胞中没有变化。胰岛素（1 ~ 2 U/kg/d）对糖尿病家兔的抗氧化活性有抑制作用。这些抗氧化活性也测定在糖尿病的肝脏和肾脏。在糖尿病肝脏中观察到细胞防御活性和胰岛素预防活性下降的类似下降，而肾脏中的这些抗氧化酶活性对糖尿病有抵抗力。糖尿病肝脏中谷胱甘肽合成酶γ -谷氨酰半胱氨酸合成酶的活性下降，这可能是谷胱甘肽浓度下降的原因。这些结果表明，在糖尿病家兔的肝脏内皮细胞中观察到GSH及其相关酶活性受损，而胰岛素治疗可以预防这些损伤。抗氧化活性的降低可能在与糖尿病相关的病理谱中具有重要意义。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