Brox L, Ng A, Pollock E, Belch A
Cancer Res. 1984 Mar;44(3):934-7.
There is a progressive loss of human T-lymphocyte viability upon incubation with deoxycoformycin, an adenosine deaminase inhibitor, and low concentrations of deoxyadenosine (drug concentration that reduced cell count at 48 hr after initiation to 50% of value for untreated control culture, less than 1 microM). The loss of viability was evidenced by vital staining with fluorescein diacetate and by changes in forward single light scatter measured by flow cytometry. This loss of lymphocyte viability is detectable 18 to 20 hr after the addition of deoxyadenosine and is earlier than has been reported by other investigators using trypan blue as the vital stain. Alkaline elution studies show that the incubation of T-lymphocytes with the combinations of deoxycoformycin and deoxyadenosine gives rise to DNA single-strand breaks. These DNA strand breaks are dose and time dependent and are readily detected 4 hr after the addition of deoxyadenosine. These DNA lesions are not observed with deoxycoformycin or deoxyadenosine alone. Incubations of T-lymphocytes with deoxycoformycin and deoxyadenosine (1 and 5 microM) for 7 hr result in DNA strand breaks with a frequency of 145 and 280 rad equivalents, respectively. Preliminary studies indicate that the ability of lymphocytes to repair this damage is dependent upon deoxyadenosine concentration and exposure time. The relationship of these DNA lesions to loss of lymphocyte viability in the presence of deoxycoformycin and deoxyadenosine remains to be established.
用腺苷脱氨酶抑制剂脱氧助间型霉素和低浓度的脱氧腺苷（起始后48小时使细胞计数降至未处理对照培养物值的50%的药物浓度，小于1微摩尔）孵育人T淋巴细胞时，其活力会逐渐丧失。活力丧失通过用二乙酸荧光素进行活细胞染色以及通过流式细胞术测量的前向单光散射变化得以证实。在加入脱氧腺苷后18至20小时可检测到淋巴细胞活力丧失，这比其他使用台盼蓝作为活细胞染色剂的研究者所报告的时间更早。碱性洗脱研究表明，将T淋巴细胞与脱氧助间型霉素和脱氧腺苷组合孵育会导致DNA单链断裂。这些DNA链断裂具有剂量和时间依赖性，在加入脱氧腺苷后4小时即可轻易检测到。单独使用脱氧助间型霉素或脱氧腺苷时未观察到这些DNA损伤。将T淋巴细胞与脱氧助间型霉素和脱氧腺苷（1和5微摩尔）孵育7小时分别导致DNA链断裂频率为145和280拉德当量。初步研究表明，淋巴细胞修复这种损伤的能力取决于脱氧腺苷浓度和暴露时间。在存在脱氧助间型霉素和脱氧腺苷的情况下，这些DNA损伤与淋巴细胞活力丧失之间的关系仍有待确定。
