Gruhn K
Sektion Tierproduktion und Veterinärmedizin, Karl-Marx-Universität Leipzig, Wissenschaftsbereich Tierernährungschemie.
Arch Tierernahr. 1987 Feb;37(2):129-36. doi: 10.1080/17450398709425342.
For studying the incorporation of the 15N labelled urea into individual organs and tissues 3 colostomized laying hens were butchered after they had received 1% urea (96.06 atom-% 15N excess) with a high quality ration over a period of six days and after receiving conventional urea for another two days. Nitrogen and atom-% 15N excess (15N') were determined in the bones, the feathers and the remaining body (skin, lungs and windpipe, head with comb and wattle, lower leg without bones and with skin, pancreas and fatty tissue). In the remaining body the atom-% 15N' was determined in 15 amino acids. The labelling in the remaining body and the bones was approximately the same and averaged 0.37 atom-% 15N'. A significantly lower relative frequency could be detected in the feathers. The lysine of the remaining body contained only 0.04 atom-% 15N', tyrosine 0.06, histidine and arginine 0.07. The phenylalanine and proline molecules were labelled with 0.11 atom-% 15N'. Most 15N' was incorporated in serine and glutamic acid with over 0.30 atom-%. In the six non-essential amino acids out of the 15 amino acids studied, 48.6 of the non isotopic nitrogen of the total N of the remaining body and 70.7% of the isotopic nitrogen of total 15N' could be detected. Consequently the urea-N is mainly used for the synthesis of the non-essential amino acids, with its utilization being very low.
为了研究15N标记的尿素在各个器官和组织中的掺入情况，3只做了结肠造口术的蛋鸡在接受1%尿素（15N过量96.06原子%）与高质量日粮6天后，再接受常规尿素2天，之后被宰杀。测定了骨骼、羽毛和剩余身体部分（皮肤、肺和气管、带鸡冠和肉垂的头部、去骨带皮小腿、胰腺和脂肪组织）中的氮和15N过量原子%（15N'）。在剩余身体部分中，测定了15种氨基酸中的15N'原子%。剩余身体部分和骨骼中的标记情况大致相同，平均为0.37原子% 15N'。在羽毛中检测到相对频率明显较低。剩余身体部分的赖氨酸仅含0.04原子% 15N'，酪氨酸含0.06原子%，组氨酸和精氨酸含0.07原子%。苯丙氨酸和脯氨酸分子的标记为0.11原子% 15N'。大部分15N'掺入丝氨酸和谷氨酸中，超过0.30原子%。在所研究的15种氨基酸中的6种非必需氨基酸中，可检测到剩余身体部分总氮中非同位素氮的48.6%和总15N'中同位素氮的70.7%。因此，尿素氮主要用于非必需氨基酸的合成，但其利用率很低。
