Steinert Robert E, Landrock Maria F, Horowitz Michael, Feinle-Bisset Christine
Discipline of Medicine, The University of Adelaide, Royal Adelaide Hospital, Adelaide, Australia.
NHMRC Center of Research Excellence in Translating Nutritional Science to Good Health, Adelaide, Australia.
J Neurogastroenterol Motil. 2015 Jul 30;21(3):404-13. doi: 10.5056/jnm14143.
BACKGROUND/AIMS: Dietary proteins have potent eating-inhibitory and glucose-lowering effects, which may be mediated via effects of amino acids on gastrointestinal hormone and motor function, although little information is available. We have now evaluated the effects of L-phenylalanine (L-Phe) and L-glutamine (L-Gln) on antropyloroduodenal motility and plasma cholecystokinin (CCK) concen-trations.
Two double-blind, 3-way cross-over studies were performed, each including 10 healthy, normal-weight men. We determined the antropyloroduodenal motor and plasma CCK responses to 90-minute intraduodenal infusions of L-Phe (study A) or L-Gln (study B), each at 0.15 kcal/min (total 13.5 kcal), or 0.45 kcal/min (total 40.5 kcal), or saline (control), in randomized fashion.
Intraduodenal L-Phe at 0.45 kcal/min, but not at 0.15 kcal/min, suppressed antral (P < 0.01), and stimulated phasic (P < 0.01), but not tonic, pyloric, or duodenal pressures, while L-Phe at both 0.15 kcal/min and 0.45 kcal/min stimulated plasma CCK. In contrast, L-Gln had no effect on antral, duodenal or pyloric pressures, or plasma CCK.
Intraduodenal infusions of L-Phe and L-Gln, in doses of 0.15 kcal/min and 0.45 kcal/min for 90 minutes, have different effects on antropyloroduodenal motility and CCK in normal-weight men. The modulation of antral and pyloric pressures and CCK may contribute to the eating-inhibitory effects of oral L-Phe, possibly through the slowing of gastric emptying.
背景/目的：膳食蛋白质具有强大的抑制进食和降低血糖的作用，尽管相关信息较少，但这些作用可能是通过氨基酸对胃肠激素和运动功能的影响来介导的。我们现在评估了L-苯丙氨酸（L-Phe）和L-谷氨酰胺（L-Gln）对胃幽门十二指肠运动和血浆胆囊收缩素（CCK）浓度的影响。
进行了两项双盲、三交叉研究，每项研究包括10名健康、体重正常的男性。我们以随机方式确定了胃幽门十二指肠运动和血浆CCK对90分钟十二指肠内输注L-Phe（研究A）或L-Gln（研究B）的反应，输注剂量分别为0.15千卡/分钟（总计13.5千卡）、0.45千卡/分钟（总计40.5千卡）或生理盐水（对照）。
十二指肠内输注0.45千卡/分钟的L-Phe可抑制胃窦压力（P<0.01），刺激相性压力（P<0.01），但不影响紧张性压力、幽门压力或十二指肠压力，而0.15千卡/分钟和0.45千卡/分钟的L-Phe均可刺激血浆CCK。相比之下，L-Gln对胃窦、十二指肠或幽门压力以及血浆CCK均无影响。
在体重正常的男性中，以0.15千卡/分钟和0.45千卡/分钟的剂量进行90分钟的十二指肠内输注L-Phe和L-Gln，对胃幽门十二指肠运动和CCK有不同影响。胃窦和幽门压力以及CCK的调节可能有助于口服L-Phe的抑制进食作用，可能是通过减缓胃排空来实现的。
