Thompson K M, Haibach H, Evenson J K, Sunde R A
Nutritional Sciences Program, University of Missouri, Columbia MO 65211, USA.
J Nutr. 1998 Aug;128(8):1289-95. doi: 10.1093/jn/128.8.1289.
We have previously shown that changes in glutathione peroxidase-1 (GPX1; H2O2:oxidoreductase, EC 1.11.1.9), plasma thyroid hormone and glutathione-S-transferase were not associated with changes in growth observed in second-generation (F2) severely Se-deficient rats; we also found that liver phospholipid hydroperoxide glutathione peroxidase (GPX4; EC 1.11.1.12) activity falls in first-generation (F1) Se-deficient rats to 41% of levels in Se-adequate rats. The purposes of this study were to determine the effect of F2 Se deficiency on GPX4 and to detect early changes in Se parameters associated with growth after single, small Se injections. Se-deficient male F2 weanling rats were randomly divided into two groups and fed a Se-deficient crystalline amino acid (0.003 microg Se/g diet; -Se) diet or that diet supplemented for 14 d with 0.2 microg Se/g diet (+Se) as Na2SeO3. Growth of -Se rats was 55% of the rate of +Se rats. Liver Se, GPX1 activity, GPX4 activity and testis GPX4 activity in -Se rats at 14 d were 1, 2, 23 and 13%, respectively, of levels in +Se rats. In a series of experiments, additional F2 male weanling rats were fed the -Se diet for 14 d and then were given an intraperitoneal single saline injection of 0, 1 or 5 microg Se/100 g body weight (BW) as Na2SeO3 and killed 1 or 7 d later. Rats injected with 1 or 5 microg Se/100 g BW grew 36 or 48%, respectively, above the rate of saline-injected rats. Liver Se concentration increased 367% and testis GPX4 activity doubled in rats 1 d after injection of 1 microg Se/100 g BW compared with saline-injected rats; these parameters were further elevated with 5 microg Se/100 g BW injections. Increases in liver Se and testis GPX4 activity were the parameters best associated with improved growth after Se injection, but the molecular role for Se in growth remains unclear.
我们之前已经表明，谷胱甘肽过氧化物酶-1（GPX1；H2O2：氧化还原酶，EC 1.11.1.9）、血浆甲状腺激素和谷胱甘肽-S-转移酶的变化与第二代（F2）严重缺硒大鼠生长的变化无关；我们还发现，第一代（F1）缺硒大鼠肝脏中的磷脂氢过氧化物谷胱甘肽过氧化物酶（GPX4；EC 1.11.1.12）活性降至硒充足大鼠水平的41%。本研究的目的是确定F2代缺硒对GPX4的影响，并检测单次小剂量注射硒后与生长相关的硒参数的早期变化。将缺硒的雄性F2代断奶大鼠随机分为两组，分别喂食缺硒的结晶氨基酸（0.003微克硒/克饲料；-Se）饲料或添加了0.2微克硒/克饲料（+Se）的该饲料，持续14天，添加的硒以亚硒酸钠形式存在。-Se组大鼠的生长速度是+Se组大鼠的55%。14天时，-Se组大鼠肝脏中的硒、GPX1活性、GPX4活性和睾丸中的GPX4活性分别为+Se组大鼠相应水平的1%、2%、23%和13%。在一系列实验中，另外的F2代雄性断奶大鼠先喂食-Se饲料14天，然后腹腔注射0、1或5微克硒/100克体重（BW）的亚硒酸钠生理盐水，1天或7天后处死。注射1或5微克硒/100克BW的大鼠生长速度分别比注射生理盐水的大鼠快36%或48%。与注射生理盐水的大鼠相比，注射1微克硒/100克BW的大鼠在注射1天后肝脏中的硒浓度增加了367%，睾丸中的GPX4活性翻倍；注射5微克硒/100克BW后，这些参数进一步升高。肝脏中硒的增加和睾丸中GPX4活性的增加是与注射硒后生长改善最相关的参数，但硒在生长中的分子作用仍不清楚。
