Floyd R A, Yoshida T, Leigh J S
Proc Natl Acad Sci U S A. 1975 Jan;72(1):56-8. doi: 10.1073/pnas.72.1.56.
Water proton spin lattice relaxation rate (T1) was determined on tissues of rats experiencing early phases of chemical carcinogenesis. Rats were fed a fast acting carcinogen, 3'-methyldimethylaminoazobenzene, and a slower acting carcinogen, 2-acetylaminofluorene, for up to 4 weeks. T1 of blood serum and liver tissue was significantly higher than those of controls after 4 weeks of 3'-methyldimethylaminoazobenzene feeding. This was not the case for 2-acetylaminofluorene. The blood serum T1 increase reflected the onset of liver nodulation (assumed to be preneoplastic). Liver T1 values increased as the degree of nodulation increased. Blood serum T1 correlated inversely with protein content and directly with water content. Liver T1 values correlated with water content, but this was not true for spleen T1 values. Spleen T1 values were significantly lower than controls at the earliest sampling date for each carcinogen: one week for 3'-methyldimethylaminoazobenzene and 4 weeks for 2-acetylaminofluorene. The spleen T1 decrease paralleled an increase of iron detectable by electron spin resonance in this tissue. Spleen T1 decreases are probably not unique to chemical carcinogenesis.
在经历化学致癌作用早期阶段的大鼠组织上测定了水质子自旋晶格弛豫率（T1）。给大鼠喂食快速作用的致癌物3'-甲基二甲基氨基偶氮苯和作用较慢的致癌物2-乙酰氨基芴，长达4周。喂食3'-甲基二甲基氨基偶氮苯4周后，血清和肝组织的T1显著高于对照组。2-乙酰氨基芴的情况并非如此。血清T1的增加反映了肝结节（假定为癌前病变）的出现。肝T1值随着结节程度的增加而增加。血清T1与蛋白质含量呈负相关，与水分含量呈正相关。肝T1值与水分含量相关，但脾T1值并非如此。在每种致癌物的最早采样日期，脾T1值均显著低于对照组：3'-甲基二甲基氨基偶氮苯为1周，2-乙酰氨基芴为4周。脾T1的降低与该组织中通过电子自旋共振可检测到的铁的增加平行。脾T1的降低可能并非化学致癌作用所特有。
