Kato A, Diksic M, Yamamoto Y L, Feindel W
J Cereb Blood Flow Metab. 1985 Mar;5(1):108-14. doi: 10.1038/jcbfm.1985.14.
Reevaluation of lumped and rate constants is necessary when Sokoloff's 2-deoxyglucose (DG) method is used to measure glucose utilization in pathological tissue. We describe here a modification of Sokoloff's lumped constant measurement that permits simultaneous estimation of both lumped and rate constants from a single animal experiment. A subcutaneous tumor model (AA ascites tumor) was used for measurement of these constants with a procedure similar to Sokoloff's that kept the plasma tracer concentration constant. Measured constants were as follows: lumped constant, 0.654 +/- 0.081; k1, 0.196 +/- 0.038 min-1; k2, 0.262 +/- 0.067 min-1; k3, 0.117 +/- 0.044 min-1. These constants were used to quantify glucose utilization in the implanted brain tumor. To test the validity of this method, we compared a fraction of the free DG pool calculated using the tumor constants with a fraction measured directly by chromatographic analysis of tissue samples from both subcutaneous tumor and implanted brain tumor. The values derived by chemical analysis agreed well with those predicted by the calculations. The value of k4 varied from 0.0031 +/- 0.0018 min-1 for the tumor tissue to 0.0214 +/- 0.0024 min-1 for tumors with a large necrotic center. This method would be especially useful when applied to xenograft human gliomas in nude mice for quantification of glucose utilization in human gliomas by means of positron emission tomography.
当使用索科洛夫的2-脱氧葡萄糖（DG）方法测量病理组织中的葡萄糖利用情况时，重新评估集总常数和速率常数是必要的。我们在此描述了对索科洛夫集总常数测量方法的一种改进，该方法允许从单个动物实验中同时估计集总常数和速率常数。使用皮下肿瘤模型（AA腹水瘤），通过与索科洛夫方法类似的程序来测量这些常数，该程序可保持血浆示踪剂浓度恒定。测得的常数如下：集总常数，0.654±0.081；k1，0.196±0.038 min⁻¹；k2，0.262±0.067 min⁻¹；k3，0.117±0.044 min⁻¹。这些常数用于量化植入脑肿瘤中的葡萄糖利用情况。为了测试该方法的有效性，我们将使用肿瘤常数计算得到的游离DG池的一部分与通过对皮下肿瘤和植入脑肿瘤组织样本进行色谱分析直接测量得到的一部分进行了比较。化学分析得出的值与计算预测的值非常吻合。k4的值从肿瘤组织的0.0031±0.0018 min⁻¹到有大坏死中心的肿瘤的0.0214±0.0024 min⁻¹不等。当该方法应用于裸鼠体内的人胶质瘤异种移植物，通过正电子发射断层扫描来量化人胶质瘤中的葡萄糖利用情况时，将特别有用。
