Duydu Yalçin, Ustündağ Aylin, Aydin Ahmet, Eken Ayşe, Dündar Kadir, Uzun Günal
Department of Toxicology, Faculty of Pharmacy, Ankara University, Tandodan, Ankara 06100, Turkey.
Environ Mol Mutagen. 2006 Apr;47(3):185-91. doi: 10.1002/em.20184.
Treatment of cells with hyperbaric oxygen (HBO) results in the generation of reactive oxygen species and the induction of DNA damage. In the present study, we have evaluated the sister chromatid exchange (SCE) frequencies in lymphocytes from patients undergoing hyperbaric oxygen therapy (HBOT). In addition, we have determined the sensitivity of lymphocytes from those patients to SCE induction by 20 and 40 ng/ml mitomycin C (MMC). Patients undergoing HBOT for diabetic feet were exposed to 10 consecutive daily HBO treatments according to a routine therapy protocol. The study began with 12 patients; however, it was not possible to sample all of the patients at all HBOT sessions, and the number of patients gradually decreased towards the end of the HBOT. We observed a statistically significant induction in mean SCE/cell (P < 0.05; n = 11) immediately after the first session of HBOT. Relative to its frequency after the 1st treatment, the mean SCE frequency gradually decreased after the 5th and 10th HBOT sessions and reached baseline (pretherapy) levels 1 day after the last treatment in the four patients that were sampled. The mean MMC-induced SCE frequency was highest in lymphocytes sampled immediately after the first HBOT session, and significantly higher than the MMC-induced SCE frequency in cells sampled before HBOT. Unlike the case with untreated cells, MMC-induced SCE frequencies remained high in lymphocytes sampled at later stages of therapy and mean MMC-induced SCE frequencies were significantly higher (P < 0.05; n = 4) in lymphocytes sampled 1 day after the last session of HBOT than in lymphocytes sampled from these patients prior to beginning the therapy. The results indicate that HBOT induces SCE and that lymphocytes retain increased sensitivity to the genotoxicity of MMC one day after completing the HBOT.
用高压氧（HBO）处理细胞会导致活性氧的产生和DNA损伤的诱导。在本研究中，我们评估了接受高压氧治疗（HBOT）患者淋巴细胞中的姐妹染色单体交换（SCE）频率。此外，我们还确定了这些患者的淋巴细胞对20和40 ng/ml丝裂霉素C（MMC）诱导SCE的敏感性。接受HBOT治疗糖尿病足的患者按照常规治疗方案连续10天每日接受HBO治疗。研究开始时有12名患者；然而，不可能在所有HBOT疗程中对所有患者进行采样，并且在HBOT接近尾声时患者数量逐渐减少。我们观察到在第一次HBOT疗程后立即出现平均每个细胞SCE的统计学显著诱导（P < 0.05；n = 11）。相对于第一次治疗后的频率，平均SCE频率在第5次和第10次HBOT疗程后逐渐降低，并在最后一次治疗后1天在采样的4名患者中达到基线（治疗前）水平。平均MMC诱导的SCE频率在第一次HBOT疗程后立即采样的淋巴细胞中最高，并且显著高于HBOT前采样细胞中的MMC诱导的SCE频率。与未处理细胞的情况不同，在治疗后期采样的淋巴细胞中MMC诱导的SCE频率仍然很高，并且在最后一次HBOT疗程后1天采样的淋巴细胞中平均MMC诱导的SCE频率显著高于（P < 0.05；n = 4）这些患者在开始治疗前采样的淋巴细胞。结果表明，HBOT诱导SCE，并且淋巴细胞在完成HBOT后一天对MMC的遗传毒性保持增加的敏感性。
