Turnover rate of normal blood lymphocytes and exchangeable pool size in man, calculated from analysis of chromosomal aberrations sustained during extracorporeal irradiation of the blood.
Turnover rate of normal blood lymphocytes and exchangeable pool size in man, calculated from analysis of chromosomal aberrations sustained during extracorporeal irradiation of the blood.
复制标题
人体正常血液淋巴细胞的周转率和可交换池大小，根据血液体外照射期间持续的染色体畸变分析计算得出。
作者：
E. Field;H. Sharpe;K. B. Dawson;V. Andersen;S. Killmann;E. Weeke
对四名肾移植前接受体外照射血液(ECIB)免疫抑制治疗的患者的淋巴细胞动力学进行了研究。这项技术包括分析淋巴细胞在辐射过程中所承受的染色体畸变，以及在植物血凝素(PHA)刺激的培养中表现出来的染色体畸变。含有异常的淋巴细胞可以被认为是标记的，这种形式的标记的优点是它不需要对体外的淋巴细胞进行操作。初步实验证实，在300-400rad剂量的照射下，约有一半的淋巴细胞在培养中不能进行有丝分裂，每个淋巴细胞在ECIB疗程结束时的畸变率与开始时相同。经照射的淋巴细胞在血液中的平均停留时间不到2分钟，在照射的最初几个小时，它们被组织池中的淋巴细胞以一种速度取代，以至于外周血计数没有明显的下降。这些发现表明，很大一部分血管内皮细胞充当受损淋巴细胞的过滤器，最初受损的细胞以每小时一个血池的速度被替换，这可能代表了血液淋巴细胞的正常周转时间。根据一系列关于辐照细胞动力学的基本假设，用两种方法计算了总可交换淋巴细胞池的大小。根据最有可能的估计，总池中包含的细胞数量大约是血液中循环细胞的30倍。在300rad的照射剂量下，42%的淋巴细胞存活，10%-19%的淋巴细胞存活380rad。
Lymphocyte kinetics have been studied in four patients treated by extracorporeal irradiation of the blood (ECIB) for immunosuppressive purposes prior to renal transplantation. The technique involves the analysis of chromosomal aberrations sustained by lymphocytes during irradiation and demonstrable in cultures stimulated with phytohaemagglutinin (PHA). Lymphocytes containing aberrations may be regarded as labeled, and this form of labeling has the advantage that it does not require the manipulation of lymphocytes outside the body. Preliminary experiments established that about half of lymphocytes irradiated with doses of 300-400 rad fail to undergo mitosis in culture and that the aberration yield per lymphocyte is the same at the end of a course of ECIB as at the beginning. Irradiated lymphocytes were found to have a mean residence time in the blood of less than 2 min, and for the first few hours of irradiation they were replaced by lymphocytes from tissue pools at a rate such that there was no appreciable fall in the peripheral count. These findings imply that a large proportion of the vascular endothelium acts as a filter for damaged lymphocytes and that initially damaged cells were replaced at the rate of one blood pool per hour; this may represent the normal turnover time of blood lymphocytes. The size of the total exchangeable lymphocyte pool was calculated by two methods depending on a series of basic assumptions concerning the kinetics of irradiated cells. According to the most likely estimate, the total pool contains some 30 times as many cells as circulate in the blood. Forty-two per cent of lymphocytes survived an irradiation dose of 300 rad, 10%-19% survived 380 rad.