Niiyama M, Deguchi E, Kagota K, Namioka S
Am J Vet Res. 1979 May;40(5):716-8.
Two experiments were done to determine whether pigs possess the ability to absorb amino acids synthesized from urea nitrogen by indigenous microbes in the large intestine. Incorporation of [15N]urea into amino acid fractions of bacterial cells from the rectum and of the deproteinized incubated medium were examined in an experiment in vitro. The isotope was incorporated into 17 amino acids and the ammonia fraction of these samples. The absorption of the microbial amino acids from the colon was investigated by determination of the 15N concentration of the free amino acids in the venous blood of the colon after infusion of the 15N-labeled microorganisms into the cecum. The increase of 15N concentration was also observed in the plasma-free amino acids (threonine, isoleucine, phenylalanine, lysine, histidine, arginine, aspartic acid, serine, alanine, cystine) of the blood from the colic branch of the ileocolic vein. The results of these experiments indicated that pigs have the ability to utilize the microbial amino acids synthesized from urea nitrogen in the large intestine.
进行了两项实验，以确定猪是否具有吸收大肠中本地微生物由尿素氮合成的氨基酸的能力。在一项体外实验中，检测了[15N]尿素掺入直肠细菌细胞和脱蛋白培养介质氨基酸组分的情况。该同位素掺入了这些样品的17种氨基酸和氨组分中。通过将15N标记的微生物注入盲肠后，测定结肠静脉血中游离氨基酸的15N浓度，研究了结肠中微生物氨基酸的吸收情况。在回结肠静脉结肠支血液的无血浆氨基酸（苏氨酸、异亮氨酸、苯丙氨酸、赖氨酸、组氨酸、精氨酸、天冬氨酸、丝氨酸、丙氨酸、胱氨酸）中也观察到了15N浓度的增加。这些实验结果表明，猪具有利用大肠中由尿素氮合成的微生物氨基酸的能力。
