饲料蛋白质水平对大鼠蛋白质、锌、铁和铜吸收利用的影响

Ｗｉｓｔａｒ纯品系断奶雄性大鼠３２只，随机分成４组，喂纯合成饲料。第１、２、３、４组饲料含蛋白质分别为５％、１０％、２０％和１０％，其它成份相同，第５０天只有第４组改喂以无氮饲科并与其它三组同样收集５天粪、尿，测定氮及锌、铁、铜的代谢量，第５６天处死大鼠，测毛和肝、肾、脑、睾丸、胫骨中锌、铁、铜的含量。结果表明：低蛋白质水平组影响大鼠体重增长和蛋白质代谢，机体组织锌、铁，铜含量降低，经粪便排出锌、铁量增加，锌和铁的吸收与存留显著降低。本文还对蛋白质营养水平不同所致的锌、铁、铜营养状况缺乏时毛中锌、铁、铜含量作为诊断指标的意义进行了探讨。

THE EFFECT OF DIFFERENT PROTEIN INTAKE LEVELS oN THE UTILIZATION OF PROTEIN,ZINC,IRON AND COPPER lN RATS

hirty-two male weanling Wistar rats were divided randomly into 4groups.All of their diets were synthetics according to AOAC. The lst,2nd,3rd and 4th groups were given diets containing 5%,10%,20%and 10%of protein respectively,After feeding in stainless steel cage single for 50days,the 4th group was given nitrogen free diet,other groups didn't change.Then the feces and urine of rats were collected on 5 consecutive days,ni-trogen,zinc,iron and copper contents were determined.Tlie rats were killedon 56th days,and the contents of Zinc,iron and copper were determined inhai,liver,kidney,testes and tibias.The body weight gain,nitrogen utili-zation,the contents of zinc,iron and copper of organs of rats fed on thelowest protein level were decreased significantly,The zinc and iron con-tents in feces were increased significantly,i.e.the zinc and iron absorptionand retention were decredsed significantly. This would be improved by in-creasing protein intake.The possibility of using contents of zinc,iron andcopper in hair as an index for diagnosing deficiencies of zinc,iron and cop-per induced by lower protein intake、was discussed.