Olive P L, Durand R E
Cancer Res. 1983 Jul;43(7):3276-80.
Binding of several nitroheterocycles by mammalian cells is a function of the ambient oxygen concentration; anoxic single cells bind up to 10 times as much of these drugs as do aerobic cells. We thus hypothesized that fluorescent nitroheterocyles could be used to quantitate the fraction of hypoxic cells in multicell systems, and this was tested in multicell spheroids using a relatively nontoxic nitrofuran, trans-5-amino-3-[(5-nitro-2-furyl)vinyl]-1,2,4-oxadiazole. Binding of trans-5-amino-3-[(5-nitro-2-furyl)vinyl]-1,2,4-oxadiazole, as quantified by flow cytometry, was highly responsive to external oxygen concentration. To assess the relevance of the observed fluorescence, fluorescence-activated cell sorting was used to examine the radiosensitivity of cells as a function of their fluorescence intensity. The most fluorescent were indeed the most radioresistant (i.e., contained the least oxygen). Additional results confirm the general feasibility of using fluorescent nitroheterocycles as hypoxic cell probes but also reveal that cellular binding of these agents is not exclusively dependent upon cellular oxygen content.
哺乳动物细胞对几种硝基杂环的结合是环境氧浓度的函数；缺氧的单细胞结合这些药物的量是有氧细胞的10倍之多。因此，我们推测荧光硝基杂环可用于定量多细胞系统中缺氧细胞的比例，并使用一种相对无毒的硝基呋喃——反式-5-氨基-3-[(5-硝基-2-呋喃基)乙烯基]-1,2,4-恶二唑在多细胞球体中进行了测试。通过流式细胞术定量，反式-5-氨基-3-[(5-硝基-2-呋喃基)乙烯基]-1,2,4-恶二唑的结合对外部氧浓度高度敏感。为了评估观察到的荧光的相关性，使用荧光激活细胞分选来检查细胞的放射敏感性与其荧光强度的关系。荧光最强的细胞确实是最抗辐射的（即含氧量最低）。其他结果证实了使用荧光硝基杂环作为缺氧细胞探针的总体可行性，但也表明这些试剂与细胞的结合并不完全取决于细胞含氧量。
