Olive P L
Int J Radiat Oncol Biol Phys. 1985 Nov;11(11):1947-54. doi: 10.1016/0360-3016(85)90276-7.
Fluorescent nitroheterocycles may be useful as probes for cellular hypoxia. Reductive metabolism of AF-2 (cis 2-(2-furyl)-3-(5-nitro-2-furyl)acrylamide) and NFVO (trans-5-amino-3((5-nitro-2-furyl)vinyl)1,2,4-oxadiazole) results in intracellular accumulation of fluorescent molecules; the mean cellular fluorescence has previously been shown to be related to the cellular oxygen content during incubation in vitro. However, factors in addition to oxygen and nitroreductive activity may also affect cellular accumulation of these drugs. The stability of cellular fluorescence and possible diffusion of metabolites were examined by flow cytometric analysis of mouse and hamster fibroblasts exposed to NFVO and AF-2. Incubation of cells with 14C-AF-2 allowed calibration of the flow cytometer for AF-2 fluorescence; 5 X 10(8) molecules/cell resulted in double the spontaneous cellular fluorescence. Cellular fluorescence was stable for days after exposure to AF-2, and no evidence of transfer between exposed and unexposed cells was observed. For concentrations resulting in less than 5 X 10(9) AF-2 adducts/cell, all of the metabolites could be accounted for intracellularly. Therefore, it is unlikely that transfer of reduced nitroheterocycles occurs between cells.
荧光硝基杂环化合物可能作为细胞缺氧的探针。AF - 2（顺式2 - (2 - 呋喃基)-3 - (5 - 硝基 - 2 - 呋喃基)丙烯酰胺）和NFVO（反式 - 5 - 氨基 - 3 - ((5 - 硝基 - 2 - 呋喃基)乙烯基)-1,2,4 - 恶二唑）的还原代谢导致荧光分子在细胞内积累；先前已表明，在体外培养期间，平均细胞荧光与细胞氧含量有关。然而，除了氧气和硝基还原活性外，其他因素也可能影响这些药物在细胞内的积累。通过对暴露于NFVO和AF - 2的小鼠和仓鼠成纤维细胞进行流式细胞术分析，研究了细胞荧光的稳定性和代谢产物可能的扩散情况。用14C - AF - 2孵育细胞可对流式细胞仪进行AF - 2荧光校准；每细胞5×10⁸个分子导致细胞自发荧光增加一倍。暴露于AF - 2后，细胞荧光可持续数天稳定，未观察到暴露细胞与未暴露细胞之间有转移的迹象。对于导致每细胞少于5×10⁹个AF - 2加合物的浓度，所有代谢产物都可在细胞内得到解释。因此，还原硝基杂环化合物在细胞间转移的可能性不大。
