PROTEIN-ABSORPTION AND ENERGY DIGESTIBILITY AT HIGH-ALTITUDE
PROTEIN-ABSORPTION AND ENERGY DIGESTIBILITY AT HIGH-ALTITUDE
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DOI：
10.1152/jappl.1992.73.6.2425
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发表时间：
1992-12-01
影响因子：
3.3
通讯作者：
CERRETELLI, P
中科院分区：
文献类型：
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作者：
KAYSER, B;ACHESON, K;CERRETELLI, P
为了检验膳食蛋白质吸收不良是长时间海拔暴露期间观察到的体重减轻的部分原因这一假设，6名健康男性受试者[31.8 +/- 4.5（SD）yr]在122和5，000 m处口服N-15标记的大豆蛋白和静脉注射[N-15]甘氨酸。从随后的4天总尿液和粪便池中，通过质谱法测定给药N-15的不同级分。在海拔暴露开始和结束时测量体重和皮褶厚度。此外，通过3天的饮食控制和相应粪便池能量含量的绝热弹量热法评估，评估了在海拔高度饮食的总可消化能量。在高原暴露期间，受试者的体重平均下降3%。从皮褶厚度测量值估计，在海拔高度的脂肪量损失为9%。蛋白质吸收，计算为100 - [摄入N-15大豆蛋白后N-15的粪便排泄（给药剂量%）-注射N-15甘氨酸后N-15的粪便排泄（给药剂量的%）]，与海平面相比，（分别为96和97%），在海拔高度的总消化能，计算为粪便中100%未消化的总能量，达到96%。结论是，至少在海拔5,000米以下，吸收不良在与海拔有关的体重减轻中不起作用。
To test the hypothesis that malabsorption of dietary protein is partly responsible for the weight loss observed during prolonged altitude exposure, six healthy male subjects [31.8 +/- 4.5 (SD) yr] received N-15-labeled soya protein by mouth and [N-15]glycine intravenously at 122 and 5,000 m. From the subsequent 4-day total urine and fecal pools, the different fractions of the administered N-15 were determined by mass spectrometry. Weight and skinfold thickness were measured at the beginning and end of the altitude exposure. In addition, the overall digestible energy of the diet at altitude was assessed by a 3-day diet control and adiabatic bomb calorimetric assessment of the energy content of the corresponding fecal pool. The average decrease of the subjects' weight during altitude exposure was 3%. Loss of fat mass at altitude estimated from the skinfold measurements was 9%. Protein absorption, calculated as 100 - [fecal excretion of N-15 after ingestion of N-15 soya protein (% of dose given) - fecal excretion of N-15 after injection of N-15 glycine (% of dose given)], was not significantly impaired at altitude compared with sea level (96 vs. 97%, respectively), and overall digestible energy at altitude, calculated as 100 - percent undigested gross energy in the feces, amounted to 96%. It is concluded that, at least up to an altitude of 5,000 m, malabsorption does not play a role in altitude-related weight loss.