Briviba K, Fraser G, Sies H, Ketterer B
Institut für Physiologische Chemie I, Heinrich-Heine-Universität Düsseldorf, Germany.
Biochem J. 1993 Sep 15;294 ( Pt 3)(Pt 3):631-3. doi: 10.1042/bj2940631.
The nuclear/cytoplasmic distributions of the GSH and N-acetylcysteine conjugates of monochlorobimane (MCB) have been studied in rat hepatocytes in primary culture after microinjection into the cytoplasm. The immediately occurring fluorescence (within 1-2 s) in the nucleus was much greater than that in the cytoplasm. Other water-soluble fluorescent markers such as Cascade Blue, 6-carboxyfluorescein and Lucifer Yellow also exhibited a similar nuclear localization. MCB, which is poorly soluble in water, gave similar results whether exposed to the exterior of the cell or microinjected as a solution in ethanol. It is concluded that the fluorophores studied here diffuse into the nucleus and accumulate there, including MCB-GSH formed intracellularly from MCB and GSH. Therefore MCB may be of limited value in estimating concentrations of GSH in the nucleus and the cytoplasm, as recently suggested by Bellomo, Vairetti, Stivala, Mirabelli, Richelmi and Orrenius [(1992) Proc. Natl. Acad. Sci. U.S.A. 89, 4412-4416].
在原代培养的大鼠肝细胞中，将单氯联苯胺（MCB）的谷胱甘肽（GSH）和N - 乙酰半胱氨酸共轭物显微注射到细胞质后，研究了它们在细胞核/细胞质中的分布情况。细胞核中立即出现的荧光（在1 - 2秒内）比细胞质中的要强得多。其他水溶性荧光标记物，如级联蓝、6 - 羧基荧光素和路西法黄也表现出类似的细胞核定位。MCB在水中溶解度很低，无论是暴露于细胞外部还是以乙醇溶液形式显微注射，都得到了类似的结果。由此得出结论，这里研究的荧光团会扩散到细胞核并在那里积累，包括由MCB和GSH在细胞内形成的MCB - GSH。因此，正如Bellomo、Vairetti、Stivala、Mirabelli、Richelmi和Orrenius最近所指出的[(1992) Proc. Natl. Acad. Sci. U.S.A. 89, 4412 - 4416]，MCB在估计细胞核和细胞质中GSH的浓度方面可能价值有限。
