Reid E
Br J Cancer. 1970 Mar;24(1):128-37. doi: 10.1038/bjc.1970.16.
Earlier work on acid-soluble nucleotides and other liver constituents as affected by azo-dye carcinogenesis has now been extended, with trial of ethionine (weakly carcinogenic) and of α-naphthylisothiocyanate (noncarcinogenic). The effects of ethionine feeding on whole-tissue nucleotide levels were not dramatic, and were generally dissimilar to those produced by azo-dye feeding. However a fall in some or all of the purine nucleotides can still be regarded as a feature of hepatocarcinogenesis.A fall in mitochondrial nucleotides, as previously found in azo-dye experiments, likewise occurs with ethionine feeding, but also with α-naphthylisothiocyanate. It is suggested that the latter warrants testing as a co-carcinogen. Unlike azo-dyes, ethionine is without adverse effect on the yield of protein in cytoplasmic particles and (in common with α-naphthylisothiocyanate) it raises the yield of RNA in the supernatant fraction.In liver from ethionine-fed rats and in ethionine-induced hepatomas, the activity of enzymes concerned in UMP synthesis showed a rise more striking than that found with azo-dyes.
早期关于偶氮染料致癌作用对酸溶性核苷酸及其他肝脏成分影响的研究现已得到扩展，对乙硫氨酸（弱致癌性）和α-萘基异硫氰酸酯（非致癌性）进行了试验。喂食乙硫氨酸对全组织核苷酸水平的影响并不显著，且总体上与喂食偶氮染料所产生的影响不同。然而，某些或所有嘌呤核苷酸的减少仍可被视为肝癌发生的一个特征。正如之前在偶氮染料实验中所发现的那样，喂食乙硫氨酸会导致线粒体核苷酸减少，α-萘基异硫氰酸酯喂食也会出现这种情况。有人提出，后者作为一种助致癌物值得进行测试。与偶氮染料不同，乙硫氨酸对细胞质颗粒中的蛋白质产量没有不利影响，并且（与α-萘基异硫氰酸酯一样）会提高上清液部分中RNA的产量。在喂食乙硫氨酸的大鼠肝脏以及乙硫氨酸诱导的肝癌中，参与UMP合成的酶的活性升高比偶氮染料更为显著。
