College of Veterinary Medicine, Sichuan Agricultural University, Ya'an, Sichuan 625014, China.
Biol Trace Elem Res. 2012 Jan;145(1):47-51. doi: 10.1007/s12011-011-9160-4. Epub 2011 Aug 2.
Three hundred 1-day-old avian broilers were fed on a basic diet (0.2 mg/kg selenium) or the same diet amended to contain 1, 5, 10, and 15 mg/kg selenium supplied as sodium selenite (n = 60/group). In comparison with those of 0.2 mg/kg selenium group, the percentages of annexin V-positive splenocytes were increased in 5, 10, and 15 mg/kg selenium groups. TUNEL assay revealed that apoptotic cells with brown-stained nuclei distributed within the red pulp and white pulp of the spleens with increased frequency of occurrence in 10 and 15 mg/kg selenium groups in comparison with that of 0.2 mg/kg Se group. Sodium selenite-induced oxidative stress in spleens of chickens was evidenced by decrease in glutathione peroxidase, superoxide dismutase, and catalase activities and increase in malondialdehyde contents. The results indicate that excess dietary selenium in the range of 5-15 mg/kg of feed causes oxidative stress, which may be mainly responsible for the increased apoptosis of splenocytes in chickens.
300 只 1 日龄肉鸡分别饲喂基础日粮（0.2mg/kg 硒）或添加 0.2、1.0、5.0、10.0 和 15.0mg/kg 硒（以亚硒酸钠形式添加）的日粮（每组 60 只）。与 0.2mg/kg 硒组相比，5、10 和 15mg/kg 硒组脾组织中 Annexin V 阳性的淋巴细胞比例增加。TUNEL 检测显示，10 和 15mg/kg 硒组的脾组织红髓和白髓中有较多的棕色核染色的凋亡细胞，与 0.2mg/kg Se 组相比，发生频率增加。亚硒酸钠引起的鸡脾脏氧化应激表现为谷胱甘肽过氧化物酶、超氧化物歧化酶和过氧化氢酶活性降低，丙二醛含量增加。结果表明，饲料中硒含量超过 5-15mg/kg 会导致氧化应激，这可能是导致鸡脾淋巴细胞凋亡增加的主要原因。
