Lambert B, Morad M, Bredberg A, Swanbeck G, Thyresson-Hök M
Acta Derm Venereol. 1978;58(1):13-6.
The frequency of sister chromatid exchanges (SCE) was analysed in peripheral lymphocytes from patients receiving 8-methoxypsoralen (8-MOP) and longwave ultraviolet light (UVA) against psoriasis. The average SCE frequency in 14 patients after 3-10 weeks of clinical treatment did not differ statistically from that before treatment. UVA irradiation in vitro of blood from patients receiving 8-MOP caused a significant increase in the number of SCE. Such an increase was not observed after systemic administration of 8-MOP excluding UVA irradiation in vitro, nor after UVA irradiation in vitro in the absence of 8-MOP. Thus, the combination of oral 8-MOP administration and subsequent UVA irradiation in vitro promotes SCE in peripheral lymphocytes. However, this effect is not seen after clinical irradiation to the skin in vivo. The reason for this may be that the accumulated dose of UVA light in circulating lymphocytes, even after several weeks of clinical therapy, is not large enough to produce a significant amount of DNA damage leading to SCE, or else that DNA damage caused by the treatment is efficiency repaired during the intervals between treatments.
对接受8-甲氧基补骨脂素（8-MOP）和长波紫外线（UVA）治疗银屑病的患者外周血淋巴细胞中的姐妹染色单体交换（SCE）频率进行了分析。14例患者在临床治疗3 - 10周后的平均SCE频率与治疗前相比无统计学差异。接受8-MOP治疗的患者血液进行体外UVA照射后，SCE数量显著增加。在不进行体外UVA照射而全身给予8-MOP后，以及在没有8-MOP的情况下进行体外UVA照射后，均未观察到这种增加。因此，口服8-MOP并随后进行体外UVA照射可促进外周血淋巴细胞中的SCE。然而，在体内对皮肤进行临床照射后未观察到这种效应。其原因可能是，即使经过数周的临床治疗，循环淋巴细胞中UVA光的累积剂量也不足以产生大量导致SCE的DNA损伤，或者治疗引起的DNA损伤在治疗间隔期间得到了有效修复。
