Baruffol C, Jordi J, Camargo S, Radovic T, Herzog B, Fried M, Schwizer W, Verrey F, Lutz T A, Steingoetter A
Division of Gastroenterology and Hepatology, University of Zurich, Zurich, Switzerland.
Neurogastroenterol Motil. 2014 Jul;26(7):999-1009. doi: 10.1111/nmo.12354. Epub 2014 Jun 1.
Novel sensory inputs for the control of food intake and gastrointestinal (GI) function are of increasing interest due to the rapid increase in nutrition-related diseases. The essential amino acid L-lysine was demonstrated to have a selective impact on food intake, gastric emptying, and intestinal transit in rats, thus indicating a potential novel direct sensory input to assess dietary protein content and quality. The aim of this study was to assess translational aspects of this finding and to investigate the dose-dependent effect of L-lysine on human and rat GI function.
L-lysine doses from 0-800 mg in rats and 0.5-7.5 g in humans were analyzed for their effect on gastric emptying and GI secretion. Human GI function was assessed non-invasively using magnetic resonance imaging (MRI), rat data were acquired using standard lethal measurement methods. L-lysine dose dependently delayed gastric emptying and stimulated GI secretion in rats as reflected by residual phenol red content and increased gastric wet weight.
The dose-dependent delay in gastric emptying observed in rats was confirmed in humans with an increase in halftime of gastric emptying of 4 min/g L-lysine, p < 0.01. Moreover, a dose-dependent increase in intestinal fluid accumulation was observed (0.4 mL/min/g L-lysine, p < 0.0001). No effect on alkaline tide, glucose concentration, hematocrit, or visceral sensations was detected.
CONCLUSIONS & INFERENCES: This translational study demonstrates comparable dose-dependent effects of intragastric L-lysine on GI function in humans and rats and suggests a broader role for individual amino acids in the control of GI motility and secretion in vivo.
由于营养相关疾病的迅速增加，用于控制食物摄入和胃肠道（GI）功能的新型感觉输入受到越来越多的关注。必需氨基酸L-赖氨酸已被证明对大鼠的食物摄入、胃排空和肠道运输有选择性影响，从而表明其可能是一种评估膳食蛋白质含量和质量的新型直接感觉输入。本研究的目的是评估这一发现的转化方面，并研究L-赖氨酸对人和大鼠胃肠道功能的剂量依赖性作用。
分析了大鼠0-800mg和人类0.5-7.5g的L-赖氨酸剂量对胃排空和胃肠道分泌的影响。使用磁共振成像（MRI）对人类胃肠道功能进行非侵入性评估，使用标准致死测量方法获取大鼠数据。L-赖氨酸剂量依赖性地延迟大鼠胃排空并刺激胃肠道分泌，这通过残留酚红含量和胃湿重增加得以体现。
在人类中证实了大鼠中观察到的胃排空剂量依赖性延迟，胃排空半衰期每克L-赖氨酸增加4分钟，p<0.01。此外，观察到肠液积聚呈剂量依赖性增加（每克L-赖氨酸0.4mL/分钟，p<0.0001）。未检测到对碱潮、葡萄糖浓度、血细胞比容或内脏感觉的影响。
这项转化研究表明胃内L-赖氨酸对人和大鼠胃肠道功能具有类似的剂量依赖性作用，并提示单个氨基酸在体内控制胃肠道运动和分泌方面具有更广泛的作用。
