Correlation Between Gastric Emptying and Gastric Adaptive Relaxation Influenced by Amino Acids

Abstract

Background/AimsAmino acids have many physiological activities. We report the correlation between gastric emptying and gastric adaptive relaxation using tryptophan and amino acids with a straight alkyl chain, hydroxylated chain, and branched chain. Here we sought to further clarify the correlation between gastric emptying and gastric adaptive relaxation by using other amino acids. MethodsIn Sprague-Dawley rats, gastric emptying was evaluated by a breath test using [1-13 C] acetic acid. The expired 13 CO 2 pattern, T max , C max , and AUC 120min values were used as evaluation items. Gastric adaptive relaxation was evaluated in a barostat experiment. Individual amino acids (1 g/kg) were administered orally 30 minutes before each breath test or barostat test. ResultsL-phenylalanine and L-tyrosine did not influence gastric emptying. All other amino acids, ie, L-proline, L-histidine, L-cysteine, L-methionine, L-aspartic acid, L-glutamic acid, L-asparagine, L-arginine, L-glutamine, and L-lysine significantly delayed and inhibited gastric emptying. L-Cysteine and L-aspartic acid significantly enhanced and L-methionine and L-glutamine significantly inhibited gastric adaptive relaxation. L-Phenylalanine moved the balloon toward the antrum, suggesting strong contraction of the fundus. T max showed a significant positive correlation (r = 0.709), and C max and AUC 120min each showed negative correlations (r = 0.613 and 0.667, respectively) with gastric adaptive relaxation. ConclusionFrom the above findings, it was found that a close correlation exists between gastric emptying and adaptive relaxation, suggesting that enhanced gastric adaptive relaxation inhibits gastric emptying. (J Neurogastroenterol Motil 2017;23:400-408)

Vagus nerve stimulation promotes gastric emptying by increasing pyloric opening measured with magnetic resonance imaging

“…In vivo assessment of natural GI functions in small animals is more challenging given their smaller body size, much faster gastric motility, and the need for voluntary meal consumption. Existing methods are often invasive (or even lethal), radioactive and indirect, or employ other imaging methods that offer limited spatial, temporal, or quantitative resolution. For example, the gastric barostat method requires intubation of a balloon in the proximal or distal stomach to measure gastric motility.…”

Vagus Nerve Stimulation Promotes Gastric Emptying by Increasing Pyloric Opening Measured with Magnetic Resonance Imaging

“…In-vivo assessment of natural GI functions in small animals is more challenging given their smaller body size, much faster gastric motility, and the need for voluntary meal consumption. Existing methods are often invasive (or even lethal) (48), radioactive (49) and indirect (50), or employ other imaging methods (51) that offer limited spatial, temporal, or quantitative resolution. For example, the gastric barostat method requires intubation of a balloon in the proximal or distal stomach to measure gastric motility.…”

Wheat Protein Hydrolysate Fortified With l‐Arginine Enhances Satiation Induced by the Capsaicinoid Nonivamide in Moderately Overweight Male Subjects

“…Secretion of gastric acid facilitates the degradation of proteins into amino acids, which may contribute to the satiating effect of proteins. Dietary l ‐arginine, i.e., has been shown to reduce energy intake in rodents and to delay and inhibit gastric emptying . Furthermore, we recently demonstrated that l ‐arginine stimulated mechanisms of GAS and increased the release of serotonin in a parietal cell model.…”

“…[48] A delay in gastric emptying is known to promote early satiety. [49] However, evidence for l-arginine's effect on gastric emptying in humans is still conflicting, by describing a delay [17,50] on the one hand, and an accelerated gastric emptying [51] on the other, which may be due to application of different detection methods and study models. In addition, proteins differentially regulate gastric emptying depending on their origin, with a mostly increased gastric emptying for whey protein in comparison to cod, gluten, or casein, when administrated within a standardized test meal in an amount of 45 g. [14] In the present human intervention study, both the WPH as well as the WPH + ARG intervention delayed gastric emptying, which was analyzed using 13 C-Na-acetate as a marker.…”

“…Dietary l-arginine, i.e., has been shown to reduce energy intake in rodents [16] and to delay and inhibit gastric emptying. [17] Furthermore, we recently demonstrated that l-arginine stimulated mechanisms of GAS [18] and increased the release of serotonin in a parietal cell model.…”