Raczyński G, Buraczewski S
Arch Tierernahr. 1975 Apr;25(3):151-6. doi: 10.1080/17450397509423181.
Male Wistar rats six month old were fed on a diet containing 10% casein heated for 4 h at 140 degrees C; control rats got untreated casein. The content of available lysine (as determined according to RAO et al.) was 5.8 g/16g N in heated and 8.5 g/16 gN in untreated casein. The contents of free and total lysine and of epsilon-DNP-lysine were estimated in deproteinized portal blood plasma and in urine. In the former the contents of the remaining amino acids before and after acid hydrolysis were also determined. Deproteinized portal blood plasma of rats fed on untreated or heated casein contained, respectively, un mumoles per 10 ml: total lysine 9.0 and 9.9; free lysine 3.7 and 2.8; bound lysine (total lysine -free lysine) 5.3 and 7.1; peptide-bound lysine (determined as epsilon-DNP-lysine) 4.9 and 4.6; and epsilon-bound lysine (bound lysine - peptide-bound lysine) 0.5 and 2.6. The data indicate that lysine with blocked epsilon-amino group was released in the course of digestion of the heated casein and absorbed. This is additionally substantiated by the presence of this form of lysine in the urine of rats given heated casein.
给6个月大的雄性Wistar大鼠喂食含10%酪蛋白的饲料，该酪蛋白在140摄氏度下加热4小时；对照大鼠则喂食未处理的酪蛋白。（根据饶等人的方法测定）加热后的酪蛋白中可利用赖氨酸含量为5.8克/16克氮，未处理的酪蛋白中为8.5克/16克氮。对去蛋白的门静脉血浆和尿液中的游离赖氨酸、总赖氨酸以及ε-二硝基苯赖氨酸含量进行了估算。同时还测定了酸水解前后去蛋白门静脉血浆中其余氨基酸的含量。喂食未处理或加热酪蛋白的大鼠的去蛋白门静脉血浆中，每10毫升分别含有（以微摩尔计）：总赖氨酸9.0和9.9；游离赖氨酸3.7和2.8；结合赖氨酸（总赖氨酸 - 游离赖氨酸）5.3和7.1；肽结合赖氨酸（以ε-二硝基苯赖氨酸测定）4.9和4.6；以及ε-结合赖氨酸（结合赖氨酸 - 肽结合赖氨酸）0.5和2.6。数据表明，ε-氨基被封闭的赖氨酸在加热酪蛋白的消化过程中被释放并吸收。喂食加热酪蛋白的大鼠尿液中存在这种形式的赖氨酸，这进一步证实了这一点。
