Summary
The perfused pancreas was used for kinetic studies of leucine and phenylalanine induced insulin secretion. In a glucose-free medium, leucine stimulated insulin release over a wide range (5–80 mM). Substimulatory levels of glucose (3 mM) potentiated the leucine induced insulin release. At higher glucose concentrations (20 mM), the rate of leucine-provoked insulin release was not further enhanced. Phenylalanine (5–80 mM) did not provoke significant insulin secretion, either in the presence or in the absence of 3 mM glucose. However a dose-dependent “off-effect” was observed up to 20 mM phenylalanine. Insulin release due to glucose (20 mM) was temporarily inhibited by phenylalanine. The different kinetics for both amino acids may indicate, that receptors are involved in triggering insulin release and that glucose seems to be an important modulator of the amino acid response.
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Landgraf, R., Landgraf-Leurs, M.M.C. & Hörl, R. L-Leucine and l-phenylalanine induced insulin release and the influence of D-glucose. Diabetologia 10, 415–420 (1974). https://doi.org/10.1007/BF01221631
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DOI: https://doi.org/10.1007/BF01221631