Oral arginine does not stimulate an increase in insulin concentration but delays glucose disposal.
BACKGROUND
Ingested protein increases circulating insulin concentrations. Several years ago it was also determined that an intravenously administered mixture of 10 essential amino acids stimulated insulin secretion. Of these, arginine was the most potent. The effect was synergistic with administered glucose.


OBJECTIVE
Because the amounts of amino acid administered intravenously were very large and because ingested arginine is partially metabolized in the intestinal mucosa, we were interested in determining whether orally administered arginine stimulates a rise in circulating insulin concentration and whether arginine affects the glucose-induced rise in insulin concentration.


METHODS
Nine healthy subjects (4 women and 5 men aged 21-52 y) ingested 1 mmol arginine/kg lean body mass, 1 mmol arginine/kg lean body mass + 25 g glucose, 25 g glucose alone, and water only, in random order on separate occasions, at 0800. Blood samples were obtained at baseline and at 10-min intervals over the next 2 h and were assayed for glucose, insulin, glucagon, and amino acid concentrations. The half-time for gastric emptying was determined by scintigraphy.


RESULTS
Unlike with intravenous administration, ingested arginine did not stimulate a rise in insulin concentration. The glucagon concentration was increased. Arginine attenuated and prolonged the glucose rise when it was ingested with glucose. Gastric emptying time was similar after ingestion of glucose alone or arginine plus glucose.


CONCLUSIONS
Arginine, in an amount likely to be ingested in a high-protein meal, does not stimulate insulin secretion but attenuates the increase in glucose when given with glucose.
Gannon
Mary C
MC
Metabolic Research Laboratory and the Section of Endocrinology, Metabolism, and Nutrition, Minneapolis Veterans Administration Medical Center, Department of Food Science and Nutrition, University of Minnesota, Minneapolis 55417, USA. ganno004@tc.umn.edu
Nuttall
Jennifer A
JA
Nuttall
Frank Q
FQ
D000284:Administration, Oral; D000328:Adult; D001120:Arginine / Q000008:administration & dosage* / Q000494:pharmacology; D001786:Blood Glucose / Q000032:analysis*; D004347:Drug Interactions; D005260:Female; D005746:Gastric Emptying / Q000187:drug effects; D005934:Glucagon / Q000097:blood; D005947:Glucose / Q000008:administration & dosage / Q000494:pharmacology; D006801:Humans; D007328:Insulin / Q000097:blood*; D008297:Male; D008875:Middle Aged; D009994:Osmolar Concentration; D011897:Random Allocation; D012016:Reference Values; D013997:Time Factors
D001786:Blood Glucose; D007328:Insulin; D005934:Glucagon; D001120:Arginine; D005947:Glucose