Ingestion of Leucine + Phenylalanine with Glucose Produces an Additive Effect on Serum Insulin but Less than Additive Effect on Plasma Glucose

Abstract

Most individual amino acids stimulate insulin secretion and attenuate the plasma glucose response when ingested with glucose. We determined whether ingestion of two amino acids simultaneously with glucose would result in an additive effect on the glucose area response compared with ingestion of amino acids individually. Leucine and phenylalanine were chosen because they were two of the most potent glucose-lowering amino acids when given individually. Eight healthy subjects were studied on four separate days. Test meals were given at 0800. The first meal was a water control. Subjects then received 25 g glucose or leucine + phenylalanine (1 mmol/kg fat free body mass each) ±25 g glucose in random order. Glucose, insulin and glucagon were measured frequently for 2.5 hours thereafter. Net areas under the curves were calculated using the mean fasting value as baseline. The insulin response to leucine + phenylalanine was additive. In contrast, the decrease in glucose response to leucine + phenylalanine + glucose was less than additive compared to the individual amino acids ingested with glucose. Interestingly, the insulin response to the combination was largely due to the leucine component, whereas the glucose response was largely due to the phenylalanine component. Glucose was unchanged when leucine or phenylalanine, alone or in combination, was ingested without glucose. This trial is registered with ClinicalTrials.gov NCT01471509.

Enzymatically Modified Starch Ameliorates Postprandial Serum Triglycerides and Lipid Metabolome in Growing Pigs

“…By considering the great immediate insulin concentration, we would have rather expected a decrease in amino acid absorption with the EMS diet compared to the control diet. In this regard, additive effects of glucose and single amino acid (leucine and phenylalanine) intake on serum insulin concentration have been reported in humans [ 45 ]. Both leucine and phenylalanine were among the amino acids which concentrations were elevated by EMS diet, and might have theoretically added to the present immediate insulin response after the meal.…”

Co-Ingestion of Rice Bran Soymilk or Plain Soymilk with White Bread: Effects on the Glycemic and Insulinemic Response

“…Dietary protein has been shown to have insulin stimulating effects [ 31 , 32 , 33 ]. In a mouse model study, it was demonstrated that the presence of amino acids and insulin triggered a greater uptake of glucose into muscle tissue than insulin alone [ 34 , 35 ].…”

Quantitative Raman spectral changes of the differentiation of mesenchymal stem cells into islet-like cells by biochemical component analysis and multiple peak fitting

“…Note that the intensity increase of the three peaks at 1004, 1030, and 1208 cm −1 assigned to phenylalanine (Phe) was also observed after differentiation, in which Phe is an important cell factor for inducing insulin generation. [31][32][33] In particular, an intensity increase of the peak at 1267 cm −1 , which was assigned to amide III and related to changes in protein secondary structure, 34 was observed after differentiation, indicating that the type of synthetic protein in the amide III region might be changed after differentiation. Importantly, the peak at 665 cm −1 assigned to DNA, as described in Refs.…”