Dänicke S, Böttcher W, Simon O, Jeroch H
Institute of Animal Nutrition and Planned Crop Storage, Agricultural Faculty, Martin-Luther-University Halle-Wittenberg, Germany.
Isotopes Environ Health Stud. 2001;37(3):213-25. doi: 10.1080/10256010108033297.
An experiment was carried out to measure fractional muscle protein synthesis rates (k(s)) in broilers with injection of a flooding dose of phenylalanine (1 ml/100 g body weight of 150 mM phenylalanine; 38 atom percent excess (APE) [15N]phenylalanine). K(s) was calculated from the [15N] enrichment in phenylalanine of tissue-free and protein-bound phenylalanine using both gas chromatography mass spectrometry (GC-MS) and gas chromatography combustion isotope ratio mass spectrometry (GC-C-IRMS) for measurements after a 10 min isotope incorporation period. The tertiary-butyldimethylsilyl (t-BDMS) derivatives of phenylalanine were used for gas chromatographic separation in both systems. GC-MS and GC-C-IRMS were calibrated for a range of 7 to 37 [15N]APE and 0 to 0.62 [15N]APE, respectively, and for sample sizes of 0.45 to 4.5 nmol phenylalanine and 7 to 40 nmol phenylalanine, respectively. Reproducibility of standards as a measure of precision varied from 0.06 to 0.29 [15N]APE and from 0.0004 to 0.0018 [15N]APE in GC-MS and GC-C-IRMS, respectively. K(s) was measured in the m. pectoralis major of broilers fed rye based diets (56%) which were provided either unsupplemented (-) or supplemented (+) with an enzyme preparation containing xylanase. K(s) in breast muscles was significantly increased from 21.8%/d to 23.9%/d due to enzyme supplementation. It can be concluded from the study that the measurement of protein synthesis in broilers with the flooding dose technique can be carried out by using [15N]phenylalanine, GC-MS and GC-C-IRMS.
进行了一项实验，通过注射大剂量苯丙氨酸（150 mM苯丙氨酸，1 ml/100 g体重；38原子百分比过量（APE）[15N]苯丙氨酸）来测量肉鸡的肌肉蛋白质合成分数率（k(s)）。在10分钟的同位素掺入期后，使用气相色谱质谱法（GC-MS）和气相色谱燃烧同位素比率质谱法（GC-C-IRMS），根据游离苯丙氨酸和蛋白质结合苯丙氨酸中[15N]的丰度来计算k(s)。在这两种系统中，均使用苯丙氨酸的叔丁基二甲基甲硅烷基（t-BDMS）衍生物进行气相色谱分离。GC-MS和GC-C-IRMS分别针对7至37 [15N] APE和0至0.62 [15N] APE的范围进行校准，样品量分别为0.45至4.5 nmol苯丙氨酸和7至40 nmol苯丙氨酸。作为精密度衡量指标的标准品重现性，在GC-MS和GC-C-IRMS中分别为0.06至0.29 [15N] APE和0.0004至0.0018 [15N] APE。在以黑麦为基础日粮（56%）饲养的肉鸡胸大肌中测量k(s)，这些日粮要么不添加（-），要么添加（+）含有木聚糖酶的酶制剂。由于添加了酶，胸肌中的k(s)从21.8%/天显著增加到23.9%/天。从该研究可以得出结论，使用[15N]苯丙氨酸、GC-MS和GC-C-IRMS，可通过大剂量技术测量肉鸡的蛋白质合成。
