Hori K, Zhang Q H, Li H C, Saito S
Department of Tumour Microcirculation, Tohoku University, Sendai, Japan.
Br J Cancer. 1995 Jun;71(6):1163-8. doi: 10.1038/bjc.1995.227.
To determine whether tumour growth is influenced by circadian variations in tumour tissue blood flow, we measured changes in area doubling time of tumours (Sato lung carcinoma) within transparent chambers and changes in tissue blood flow of rat subcutaneous tumour during a light-dark cycle. Rats were subjected to an artificial light-dark cycle with light from 7 a.m. to 7 p.m. Tumour doubling times (TDTs) during the dark and the light spans were 33.5 +/- 11.9 h (n = 38, 20 rats) and 70.6 +/- 36.9 h (n = 39, 20 rats) respectively. The former was significantly shorter than the latter (P < 0.001). In addition, the larger the tumour became, the longer was the TDT during the light span (P < 0.05). Tumour tissue blood flow during the night (10 p.m.-4 a.m.) was approximately 1.5 times greater than that during the day (10 a.m.-4 p.m.). The time during which tumours actively grow and that during which tissue blood flow in tumours increases coincided. These results strongly suggest that tumour tissue blood flow is a determining influence on tumour proliferative activity and that tumour growth is influenced by circadian variations in tumour tissue blood flow.
为了确定肿瘤生长是否受肿瘤组织血流昼夜变化的影响，我们测量了透明小室内肿瘤（佐藤肺癌）面积倍增时间的变化以及大鼠皮下肿瘤在明暗周期中的组织血流变化。大鼠接受从上午7点到晚上7点的人工明暗周期。黑暗期和光照期的肿瘤倍增时间（TDT）分别为33.5±11.9小时（n = 38，20只大鼠）和70.6±36.9小时（n = 39，20只大鼠）。前者明显短于后者（P < 0.001）。此外，肿瘤越大，光照期的TDT越长（P < 0.05）。夜间（晚上10点至凌晨4点）的肿瘤组织血流比白天（上午10点至下午4点）大约高1.5倍。肿瘤活跃生长的时间与肿瘤组织血流增加的时间一致。这些结果有力地表明，肿瘤组织血流是肿瘤增殖活性的决定性影响因素，肿瘤生长受肿瘤组织血流昼夜变化的影响。
