Kobb S M, Miller A M
Department of Medicine, College of Medicine, University of Florida.
J Histochem Cytochem. 1991 Feb;39(2):165-9. doi: 10.1177/39.2.1702798.
The enzyme gamma-glutamyl transferase (gamma-GT) is involved in many biochemical systems, including the signal transduction of hematopoietic growth factors. Standard colorimetric gamma-GT assays require larger cell numbers than may be obtainable in many cases, such as with highly purified stem-cell populations. To study gamma-GT expression in limited populations, we used a histochemical stain to analyze gamma-GT semiquantitatively in cells of hematopoietic origin. Several human leukemic cell lines, including one with inducible increases in gamma-GT, were stained for gamma-GT and graded 0 through 4+ for the amount of positive granules. The gamma-GT activity demonstrated by this stain was found to be directly proportional to the gamma-GT activity obtained with a colorimetric assay and could be used to calculate approximate gamma-GT activity. This stain therefore provides a useful method for determining gamma-GT activity when limited cell numbers are available.
γ-谷氨酰转移酶（γ-GT）参与许多生化系统，包括造血生长因子的信号转导。标准比色法γ-GT检测所需的细胞数量比在许多情况下可获得的细胞数量更多，例如对于高度纯化的干细胞群体。为了研究有限群体中γ-GT的表达，我们使用组织化学染色对造血来源的细胞中的γ-GT进行半定量分析。对几种人类白血病细胞系，包括一种γ-GT可诱导增加的细胞系，进行γ-GT染色，并根据阳性颗粒数量分为0至4+级。发现这种染色所显示的γ-GT活性与比色法检测获得的γ-GT活性直接成比例，并且可用于计算近似的γ-GT活性。因此，当细胞数量有限时，这种染色为测定γ-GT活性提供了一种有用的方法。
