Department of Nutritional Physiology and Feeding, Faculty of Animal Science and Aquaculture, Agricultural University of Athens, 75 Iera Odos 11855, Athens, Greece.
Comp Biochem Physiol B Biochem Mol Biol. 2010 Mar;155(3):294-300. doi: 10.1016/j.cbpb.2009.11.017. Epub 2009 Dec 2.
A total of 128 chickens (Gallus gallus, broilers) were used to investigate the effect of organic selenium (Se) in expression of catalase (CAT) and phospholipid hydroperoxidase 4 (GPx4) genes. There were 4 replicates of 4 dietary treatments: T1 (basal diet with no added Se), T2 (T1 with 0.15 ppm Se added), T3 (T1 with 0.3 ppm Se) and T4 (T1 with 3.0 ppm Se). At 4th and 6th week, 2 chickens per replicate pen were sacrificed for whole blood and liver sample collections. Samples were analyzed for total Se by ICP-MS and gene expression by RT-PCR. Dietary supplementation with organic Se (Se-yeast) readily elevated its concentration in the tissues. GPx4 mRNA levels, pooled for both ages, of chickens fed T3 and T4 diets were significantly reduced compared to those fed diet T1 by 47% and 77% respectively, while that of T2 did not differ. Liver CAT mRNA levels at 4th week were significantly decreased as Se supplementation increased, while at 6th week, were not significantly affected by Se. The study showed that liver GPx4 mRNA levels could be down-regulated by excess of Se. It is possible that reserves built by excess of Se meet antioxidant requirements and no additional GPx4 transcription is necessary.
本研究选用 128 只肉鸡（Gallus gallus），旨在探讨有机硒（Se）对过氧化氢酶（CAT）和磷脂氢过氧化物酶 4（GPx4）基因表达的影响。试验采用 4 种日粮处理，每个处理设 4 个重复，每个重复饲养 4 只鸡，分别为：T1（基础日粮，未添加 Se）、T2（T1 日粮添加 0.15ppm Se）、T3（T1 日粮添加 0.3ppm Se）和 T4（T1 日粮添加 3.0ppm Se）。在第 4 周和第 6 周，每个重复随机选取 2 只鸡，采集全血和肝脏样品。采用 ICP-MS 检测组织中的总硒含量，采用 RT-PCR 检测基因表达情况。日粮中添加有机硒（酵母硒）可显著提高组织中的硒含量。与 T1 组相比，T3 和 T4 组鸡的 GPx4 mRNA 水平分别降低了 47%和 77%，而 T2 组与 T1 组无显著差异。第 4 周时，随着硒添加量的增加，肝脏 CAT mRNA 水平显著降低，而第 6 周时，硒对其无显著影响。本研究表明，肝脏 GPx4 mRNA 水平可能因硒过量而受到下调。过量的硒可能会产生储备，以满足抗氧化需求，因此不需要额外的 GPx4 转录。
