维生素E和硒水平对肉鸡不同自由基代谢的影响

Effects of vitamin E and selenium on the metabolism of free radicals in broilers

选用200羽14日龄健康AA肉鸡,以电子自旋共振(ESR)捕集法和生物化学法对肉仔鸡血液和组织器官的不同自由基进行直接或间接测定,探讨VE和Se对肉鸡不同自由基代谢的作用及其动态变化.结果表明:组织一氧化氮(NO)自由基水平随日粮VE含量升高而降低,二者呈负相关关系,日粮高水平Se有诱导产生NO自由基的倾向;高VE和Se日粮显著提高血清和肝脏中SOD和GSH-Px的活性,但随处理时间的延长,组织SOD活性逐渐降低,而GSH-Px活性逐渐升高,说明日粮VE和/或Se不足均会诱导机体产生O.2-、H2O2自由基,且O2.-自由基会持续大量产生,而H2O2自由基仅在缺乏初期大量产生,而后趋于缓和;低VE和/或低Se均显著提高组织MDA含量,且低Se比低VE更为显著.VE和Se对肉鸡NO、O.2-和H2O2自由基代谢的作用存在协同效应.

Taking 200 healthy＇broilers at 14 d of age as test materials, the free radicals in their blood and tissues were detected by electron spin resonance （ESR） and biochemical methods, aimed to investigate the effects of vitamin E （ VE ） and selenium （Se） on the metabolism of different free radicals and their dynamic changes in the broilers. The results showed that the content of NO free radicals in broilers tissues decreased with increasing supplementing level of VE, while high supplementation of Se tended to induce the production of NO free radicals. High supplementation of VE and Se in feeds improved the GSH-Px and SOD activities in broilers serum and liver significantly. With the extension of experimental period, the SOD activity in tissues decreased, while GSH-PX activity increased gradually, implying that the deficiency of VE and/or Se might induce the overpro- duction of O2^↑-· and H2O2 free radicals. H2O2 free radicals might be produced largely at early stage of VE and Se deficiency and declined then, while the over-production of O2^↑-· free radicals could maintain for a long time. The deficiency of VE and/or Se could improve the MDA content significantly, and Se deficiency had higher effects than VE deficiency. There were synergic effects in the metabolism of NO, O2^↑-· and H2O2 free radicals.