Shapiro B L, Smith Q T, Warick W J
Pediatr Res. 1975 Dec;9(12):885-8. doi: 10.1203/00006450-197512000-00003.
Serum glutathione reductase (NADPH-GSSG oxidoreductase, EC. 1.6.4.2 (GR)) has been examined in cystic fibrosis subjects (CF), obligate CF heterozygotes, and control subjects. Serum protein concentration was similar in the three groups. Regardless of the units used to express activity (milligrams of protein or milliters of serum) or whether or not samples were dialyzed against water or phosphate buffer, mean serum GR in CF was greater than in control subjects (P less than or equal to 0.002) in all series over several years. Under the above assay conditions no difference in serum GR between control subjects and carriers was detected. Calculated and assayed values of combined control and CF sera agreed as did expected and observed 50% activity in 1:2 sera dilutions in CF, control subjects, and carriers. Addition of FAD to incubation media did not effect enzyme activity in the three groups. Differences between CF and control subjects persisted after dialysis in membranes permitting passage of molecules of approximately 12,000 mol wt or less. These findings would tend to exclude the effect of extraneous serum factors in explaining the diffferences between CF and control subjects. The percentage of initial GR activity after four days storage (0-4 degrees) was significantly greater in CF than in control subjects (P less than 0.025). The effect of heparin on serum GR was recorded as the percentage of activity after incubation with heparin vs. activity in the standard assay for individual subjects. The effect of incubation with 5 mug/ml heparin on serum GR activity was greater in control subjects than in carriers (P less than 0.0005) and CF (P less than 0.0005). Mean serum GR activity in CF and carriers was unaffected by heparin, whereas mean activity in control subjects was decreased. In no control was the percentage of initial activity with heparin greater than the mean of CF and carrier groups. Only 3 of 20 CF and 4 of 20 carrier individuals had percentages lower than the control mean. The CF and carrier distributions were clearly different from the control distribution. Serum GR was determined in seven non-CF individuals with chronic obstructive pulmonary disease (COPD). Activity in the COPD was different from CF and no different from control subjects. In none of these controls or COPD was serum GR as great as the CF mean. Serum GR in no CF was as low as the mean of control subjects or COPD. It is concluded that serum GR activity is greater in CF than in control subjects, carriers, and non-CF COPD subjects; that the difference in activity is not attributable to an extraneous serum factor, that the activity difference is not secondary to chronic respiratory disease; that in comparison with control subjects, GR from CF serum behaves differently after storage; and that serum GR from CF and carriers behaves differently from control GR in the presence of heparin.
对囊性纤维化患者（CF）、CF致病基因携带者以及对照受试者的血清谷胱甘肽还原酶（NADPH-GSSG氧化还原酶，EC. 1.6.4.2（GR））进行了检测。三组受试者的血清蛋白浓度相似。无论用于表示活性的单位是每毫克蛋白还是每毫升血清，也无论样本是否用去离子水或磷酸盐缓冲液透析，多年来所有系列研究中CF患者的血清GR均值均高于对照受试者（P≤0.002）。在上述检测条件下，未检测到对照受试者与携带者之间血清GR存在差异。对照血清与CF血清的计算值和检测值相符，CF、对照受试者和携带者血清1:2稀释后的预期50%活性与观察值也相符。向孵育介质中添加FAD对三组的酶活性均无影响。在允许分子量约12,000或更小的分子通过的透析膜中透析后，CF与对照受试者之间的差异依然存在。这些发现倾向于排除外在血清因素对解释CF与对照受试者之间差异的影响。在0 - 4℃储存4天后，CF患者血清GR的初始活性百分比显著高于对照受试者（P＜0.025）。肝素对血清GR的影响记录为肝素孵育后活性占个体受试者标准检测活性的百分比。5μg/ml肝素孵育对血清GR活性的影响在对照受试者中大于携带者（P＜0.0005）和CF患者（P＜0.0005）。CF患者和携带者的血清GR平均活性不受肝素影响，而对照受试者的平均活性降低。在所有对照中，肝素处理后的初始活性百分比均未高于CF组和携带者组的均值。20名CF患者中只有3名以及20名携带者中只有4名的百分比低于对照均值。CF组和携带者组与对照组的分布明显不同。对7名患有慢性阻塞性肺疾病（COPD）的非CF个体测定了血清GR。COPD患者的活性与CF患者不同，但与对照受试者无差异。在这些对照受试者或COPD患者中，血清GR均未达到CF患者的均值。在非CF个体中，血清GR也未低至对照受试者或COPD患者的均值。结论为，CF患者血清GR活性高于对照受试者、携带者以及非CF的COPD患者；活性差异并非由外在血清因素导致；活性差异并非慢性呼吸系统疾病的继发表现；与对照受试者相比，CF血清中的GR在储存后表现不同；在肝素存在的情况下，CF患者和携带者的血清GR与对照GR表现不同。
