Baisch H, von Stritzky B
Institute of Biophysics and Radiobiology, University of Hamburg.
Strahlenther Onkol. 1990 Jun;166(6):430-4.
The effects of mitomycin C (MTC) alone and in combination with radiation on R1H rhabdomyosarcomas in WAG/Rij rats were studied. Growth delay was determined from tumor volume growth curves and proportion of tumor and host cells from flow cytometry measurements. Only minor growth delays were obtained with MTC at doses near the toxic level while irradiation applied in three fractions of 10 Gy in three weeks yielded growth delays of 27, 44, and 51 days measured at volumes of 2, 5, and 10 cm3, respectively. The combination of 1 micrograms/kg b.w. MTC and 10 Gy irradiation given in three weekly fractions resulted in 21, 28, and 29 days growth delay for the above tumor volumes. The lower effect of combination as compared to irradiation alone is discussed with the flow cytometry data. These data show that early after start of treatment the proportion of tumor cells remains constant in contrast to radiation alone where the fraction of tumor cells decreases because of influx of granulocytes and macrophages into the tumor. In contrast to the reduced effect on tumors the combination treatment was considerably more toxic for the animals than the single treatments.
研究了丝裂霉素C（MTC）单独及与放疗联合应用对WAG/Rij大鼠R1H横纹肌肉瘤的影响。通过肿瘤体积生长曲线确定生长延迟，并通过流式细胞术测量肿瘤细胞和宿主细胞的比例。在接近毒性水平的剂量下，MTC仅产生轻微的生长延迟，而在三周内分三次给予10 Gy的照射，在肿瘤体积分别为2、5和10 cm³时，生长延迟分别为27、44和51天。每周一次给予1 μg/kg体重的MTC与10 Gy照射联合应用，对于上述肿瘤体积，生长延迟分别为21、28和29天。结合流式细胞术数据讨论了联合治疗与单独放疗相比效果较低的原因。这些数据表明，与单独放疗不同，在治疗开始后早期，肿瘤细胞比例保持恒定，单独放疗时由于粒细胞和巨噬细胞流入肿瘤，肿瘤细胞比例会降低。与对肿瘤的效果降低相反，联合治疗对动物的毒性比单一治疗大得多。
