Glasser L, Finley P R
Transfusion. 1979 Nov-Dec;19(6):756-60. doi: 10.1046/j.1537-2995.1979.19680104104.x.
Granulocyte suspensions from eight healthy individuals were lysed ultrasonically in 0.15 M NaCl or serum. The leukolysates were tested for lactate dehydrogenase after being stored at 22 C, 5 C, -20 C and -196 C for one, two, three, four and seven days. The LDH content of granulocytes was 291 IU/10(10) cells (mean) and the enzyme had a characteristic isoenzyme pattern rich in LDH-5 with stepwise increases in each fraction from LDH-1 to LDH-5. The enzyme was unstable in saline solutions. This was marked at -20 C and related to the duration of storage. All the isoenzyme fractions showed significant inactivation. A mean 10% loss of activity occurred at -196 C. This loss was independent of the duration of storage and related to the process of freezing and thawing. Moderate inactivation occurred at room temperature while refrigerated samples were stable for four days. Serum protected the enzyme from denaturation and samples stored at -20, -196 and 22 C were stable for the seven days of the experiment.
取自八名健康个体的粒细胞悬液在0.15M氯化钠或血清中经超声裂解。白细胞裂解物在22℃、5℃、-20℃和-196℃下分别保存1、2、3、4和7天后检测乳酸脱氢酶。粒细胞的乳酸脱氢酶含量为291IU/10(10)个细胞（平均值），该酶具有富含LDH-5的特征性同工酶模式，从LDH-1到LDH-5各组分呈逐步增加。该酶在盐溶液中不稳定。在-20℃时这种不稳定性很明显，且与保存时间有关。所有同工酶组分均显示出显著失活。在-196℃时平均活性损失10%。这种损失与保存时间无关，而与冻融过程有关。在室温下发生中度失活，而冷藏样品在四天内稳定。血清可保护该酶不发生变性，在-20℃、-196℃和22℃保存的样品在实验的七天内均稳定。
