Citrulline Generation Test: What Does It Measure?
Citrulline Generation Test: What Does It Measure?
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瓜氨酸生成测试：它测量什么？
DOI：
10.1002/jpen.1462
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发表时间：
2019
期刊：
影响因子：
--
通讯作者：
Marini,JuanC
中科院分区：
文献类型：
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作者：
Mohammad,MahmoudA;Didelija,InkaC;Stoll,Barbara;Marini,JuanC
瓜氨酸生成试验（CGT）已被提议作为确定肠道功能的工具。然而，血浆瓜氨酸浓度的增加，以下的丙氨酰-谷氨酰胺的推注剂量也可能导致瓜氨酸清除减少，由于竞争与谷氨酰胺transport.Materials和MethodsA猪模型的开发，和稳定的同位素示踪剂被用来确定血浆瓜氨酸增加背后的机制，以下的丙氨酰-谷氨酰胺的推注剂量。测定血浆浓度和富集，并使用非稳态模型计算出现率、消失率和转化率。ResultsThe pig model recapitated the increase in plasma citruline observed in humans after a dose of alanyl-glutamine.二肽迅速水解成其组成氨基酸。丙氨酰-谷氨酰胺推注给药后，瓜氨酸血浆浓度和瓜氨酸出现率均增加了约45%。瓜氨酸向精氨酸的转化率和精氨酸的出现率也增加。谷氨酰胺占瓜氨酸出现率的25% ± 2%。未观察到瓜氨酸消失率的变化。ConclusionOur结果表明，单次推注剂量的丙氨酰-谷氨酰胺通过增加瓜氨酸的产生来增加血浆瓜氨酸浓度，而对瓜氨酸的处置没有任何影响。我们的研究结果强烈表明，CGT评估肠道的代谢反应，CGT可以成为一个有用的工具，以评估肠道质量和功能。
BackgroundThe citrulline generation test (CGT) has been proposed as a tool to determine gut function. However, the increase in plasma citrulline concentration that follows a bolus dose of alanyl‐glutamine may also result from a reduction in citrulline clearance due to competition with glutamine for transport.Materials and MethodsA swine model was developed, and stable isotope tracers were used to determine the mechanism behind the increase in plasma citrulline that follows a bolus dose of alanyl‐glutamine. Plasma concentrations and enrichments were determined, and a non–steady‐state model was used to calculate rates of appearance, disappearance, and conversion.ResultsThe pig model recapitulated the increase in plasma citrulline observed in humans after a dose of alanyl‐glutamine. The dipeptide was rapidly hydrolyzed to its constitutive amino acids. Both citrulline plasma concentration and citrulline rate of appearance increased by ≈45% after the bolus dose of alanyl‐glutamine. The conversion of citrulline to arginine and the rate of appearance of arginine also increased. Glutamine contributed up to 25% ± 2% of the rate of appearance of citrulline. No changes in the rate of disappearance of citrulline were observed.ConclusionOur results indicate that a single bolus dose of alanyl‐glutamine increases plasma citrulline concentration by increasing citrulline production without any effect on citrulline disposal. Our findings strongly indicate that the CGT assesses the metabolic response of the gut and that CGT can become a useful tool to evaluate gut mass and function.