Rajan S S, Wehrle J P, Li S J, Steen R G, Glickson J D
Department of Radiology and Radiological Sciences, Johns Hopkins University School of Medicine, Baltimore, MD 21205.
NMR Biomed. 1989 Nov;2(4):165-71. doi: 10.1002/nbm.1940020406.
The effects of localized gamma-irradiation on the in vivo 31P NMR spectra of RIF-1 tumors grown subcutaneously in C3H/HeN mice have been examined before and during the week after treatment. Increases in the ratio of phosphocreatine (PCr) to inorganic phosphate (Pi) and in tumor pH, and decreases in the ratio of Pi to the beta phosphorus resonance of the nucleotide triphosphates (beta NTP) were observed in irradiated tumors. The time course of changes in the 31P spectrum following treatment was the opposite of the pattern during untreated growth, and the magnitude and duration of the changes increased with increasing radiation dose, decreasing clonogenic cell survival and increasing growth delay. To examine the possibility that nontherapeutic systemic effects of the tumor irradiation were responsible for the changes observed, a number of animals bearing two tumors were examined. One tumor on each mouse was selectively irradiated. Changes in tumor volume, Pi/beta NTP, PCr/Pi, the ratio of phosphomonoesters to beta NTP, and tumor pH were all significantly different in the treated compared to the untreated tumor on each animal, indicating that these changes in 31P NMR spectra were a response to radiation therapy and not a systemic response to radiation toxicity.
已在治疗前及治疗后一周内，对皮下接种于C3H/HeN小鼠的RIF-1肿瘤的体内31P NMR谱进行了局部γ辐射效应检测。在受辐照肿瘤中，观察到磷酸肌酸（PCr）与无机磷酸（Pi）的比值以及肿瘤pH值升高，而Pi与三磷酸核苷酸的β磷共振（β NTP）的比值降低。治疗后31P谱变化的时间进程与未治疗生长期间的模式相反，且变化的幅度和持续时间随辐射剂量增加、克隆形成细胞存活率降低和生长延迟增加而增加。为了研究肿瘤辐射的非治疗性全身效应是否是观察到的变化的原因，对一些携带两个肿瘤的动物进行了检查。每只小鼠身上的一个肿瘤被选择性辐照。与每只动物未治疗的肿瘤相比，治疗后肿瘤体积、Pi/β NTP、PCr/Pi、磷酸单酯与β NTP的比值以及肿瘤pH值的变化均有显著差异，表明31P NMR谱的这些变化是对放射治疗的反应，而非对辐射毒性的全身反应。
