Tissue selenium levels in selenium-supplemented rats and their relevance in mammary cancer protection.
Tissue selenium levels in selenium-supplemented rats and their relevance in mammary cancer protection.
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补硒大鼠的组织硒水平及其与乳腺癌保护的相关性。
DOI：
10.1093/carcin/10.5.921
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发表时间：
1989
期刊：
影响因子：
4.7
通讯作者：
Hayes,C
中科院分区：
文献类型：
--
作者：
Ip,C;Hayes,C
本研究的目的是探讨是否有任何之间的相关性的抗癌作用的硒（Se）化合物和组织硒潴留在高水平的补充。在化学预防实验中使用二甲基苯并[a]蒽诱导的乳腺肿瘤模型，我们的数据表明硒代蛋氨酸在1至5 ppm Se的分级剂量范围内不如亚硒酸盐有效。在血液中，肝脏，肾脏和骨骼肌组织硒浓度总是较高的大鼠给予硒蛋氨酸相比，那些给予亚硒酸盐在每三个测试水平（1，3和5下午硒）。这种差异在血液中很小，但在肝脏和肾脏中变得更加明显，在骨骼肌中非常明显。因此，高的组织浓度或总的身体负担的硒不一定是一个指标，降低易感性致癌。硒池在维持肝脏谷胱甘肽过氧化物酶活性的生物利用度在一段时间的硒剥夺，过量的亚硒酸盐或硒代蛋氨酸加载，也进行了评估。在那些已经暴露于3 ppm硒（亚硒酸盐或硒代甲硫氨酸）的大鼠中，酶的半衰期分别为4.2和9.1天。从营养的角度来看，硒蛋氨酸可能是上级亚硒酸盐，特别是在硒不足期间的谷胱甘肽过氧化物酶的维护，但相反的似乎是真实的抗癌效力下高水平的硒补充。这些结果表明，硒化合物的营养和抗癌功效可能是不平行的。
The present study was designed to investigate whether there is any correlation between the anticarcinogenic efficacy of selenium (Se) compounds and tissue Se retention under high levels of supplementation. With the use of the dimethylbenz[a]anthracene-induced mammary tumor model in chemoprevention experiments, our data showed that selenomethionine was not as active as selenite over a graded dose range from 1 to 5 p.p.m. Se. Tissue Se concentrations in blood, liver, kidney and skeletal muscle were always higher in rats given selenomethionine compared with those given selenite at each of the three levels tested (1, 3 and 5 p.p.m.Se). The difference was only minimal in blood, but became more pronounced in the live and kidney, and was quite dramatic in the skeletal muscle. Thus a high tissue concentration or total body burden of Se is not necessarily an indicator of reduced susceptibility to carcinogenesis. The bioavailability of the Se pool in maintaining liver glutathione peroxidase activity during a period of Se deprivation, following excess selenite or selenomethionine loading, was also assessed. The half-life of decay of the enzyme was calculated to be 4.2 and 9.1 days respectively, in those rats that had already been exposed to 3 p.p.m. Se as either selenite or selenomethionine. From a nutritional viewpoint, seleno-methionine may be superior to selenite, especially with respect to maintenance of glutathione peroxidase during periods of Se inadequacy, but the reverse seems to be true in terms of anticarcinogenic potency under high levels of Se supplementation. These results suggest that the nutritional and anticarcinogenic efficacies of a given Se compound may not be paralled to each other.