Tomasi A, Benedetto C, Nilges M, Slater T F, Swartz H M, Symons M C
Biochem J. 1984 Dec 1;224(2):431-6. doi: 10.1042/bj2240431.
In previous studies we have reported on the detection of a strong e.s.r. signal in samples of normal human cervix; the signal is much reduced or absent in samples of invasive cancer of the cervix. In order to identify the species responsible for the strong signal, we have used X-, S- and Q-band e.s.r. spectroscopy. The major signal that is detectable in ground-up samples of cervix preserved at -196 degrees C has features consistent with the presence of a peroxy free radical. Good agreement with the experimental findings was obtained by computer simulation, using values for the g-tensor of gx = 2.002, gy = 2.005 and gz = 2.036. The peroxy radical is produced on grinding the normal cervix samples to a powder under liquid N2, and appears to be formed by modification of a pre-existing oxygen-containing complex. Control experiments eliminated the possibility that the strong signals seen in frozen powders prepared from normal cervix were artefacts only of the grinding procedure. Experiments with rats in vivo and with cervix samples in vitro are consistent with the conclusion that the peroxy radical is formed by disturbing the cyclo-oxygenase system that is involved in prostaglandin synthesis.
在先前的研究中，我们报告了在正常人宫颈样本中检测到强电子自旋共振（e.s.r.）信号；而在宫颈浸润癌样本中，该信号大幅减弱或消失。为了确定产生强信号的物质，我们使用了X波段、S波段和Q波段的电子自旋共振光谱法。在保存在-196℃的宫颈研磨样本中可检测到的主要信号，其特征与过氧自由基的存在一致。通过计算机模拟，使用gx = 2.002、gy = 2.005和gz = 2.036的g张量值，与实验结果取得了良好的一致性。过氧自由基是在液氮中将正常宫颈样本研磨成粉末时产生的，似乎是由预先存在的含氧化合物改性形成的。对照实验排除了在由正常宫颈制备的冷冻粉末中看到的强信号只是研磨过程假象的可能性。体内大鼠实验和体外宫颈样本实验均与过氧自由基是通过干扰参与前列腺素合成的环氧化酶系统而形成的这一结论一致。
