Braunschweiger P G, Schiffer L M
Cancer Res. 1986 Jul;46(7):3299-303.
The present series of experiments was conducted to determine the effect of dexamethasone on vascular function and cell proliferation in s.c. RIF-1 tumors. 125I-BSA, 51Cr-EDTA dilution techniques were used to evaluate dexamethasone induced changes in tumor plasma water, capillary permeability, and extracellular water volumes, while 59Fe and 51Cr labeled erythrocyte techniques were used to assess changes in tumor exchangeable erythrocyte volumes. 86RbCl distribution studies were also conducted to evaluate vascular perfusion in RIF-1 tumors after dexamethasone treatment. In this corticosteroid receptor containing tumor model, dexamethasone had profound effects on all of the measured parameters of vascular function. Reduced tumor cell proliferation after dexamethasone treatments was accompanied by reduced capillary permeability, reduced interstitial water volumes, increased plasma volumes, and reduced vascular perfusion. Serial studies after dexamethasone treatments indicated that increases in vascular perfusion preceded proliferative recovery. Intervals of maximal [3H]thymidine labeling after dexamethasone were characterized by transient increases in capillary permeability, interstitial water volumes, and tumor erythrocyte exchange with the general circulation. At intervals of maximal cell proliferation (36-48 h after dex) 86RbCl distribution in tumors was about 3 times that seen in untreated controls. The results seem to indicate that, as in edematous normal tissues, dexamethasone can have profound effects on vascular function and water compartmentalization in RIF-1 tumors.
进行本系列实验是为了确定地塞米松对皮下接种RIF-1肿瘤血管功能和细胞增殖的影响。采用¹²⁵I-BSA、⁵¹Cr-EDTA稀释技术评估地塞米松诱导的肿瘤血浆水、毛细血管通透性和细胞外水容量的变化，同时采用⁵⁹Fe和⁵¹Cr标记红细胞技术评估肿瘤可交换红细胞容量的变化。还进行了⁸⁶RbCl分布研究，以评估地塞米松治疗后RIF-1肿瘤的血管灌注情况。在这个含有皮质类固醇受体的肿瘤模型中，地塞米松对所有测量的血管功能参数都有深远影响。地塞米松治疗后肿瘤细胞增殖减少，同时伴有毛细血管通透性降低、间质水容量减少、血浆容量增加和血管灌注减少。地塞米松治疗后的系列研究表明，血管灌注增加先于增殖恢复。地塞米松处理后最大[³H]胸苷标记的时间段，其特征是毛细血管通透性、间质水容量以及肿瘤红细胞与全身循环的交换短暂增加。在最大细胞增殖间隔期（地塞米松处理后36 - 48小时），肿瘤中⁸⁶RbCl分布约为未处理对照组的3倍。结果似乎表明，与水肿的正常组织一样，地塞米松对RIF-1肿瘤的血管功能和水分布有深远影响。
