Stimulus-secretion coupling of arginine-induced insulin release. Uptake of metabolized and nonmetabolized cationic amino acids by pancreatic islets

Journal Article · Sun Jan 01 04:00:00 EST 1989 · Endocrinology; (United States)

DOI:https://doi.org/10.1210/endo-124-1-134· OSTI ID:6540920

Blachier, F; Mourtada, A; Sener, A; Malaisse, W J

In order to assess the possible role of L-arginine accumulation in islet cells as a determinant of its insulinotropic action, the uptake of L-arginine and other cationic amino acids (L-ornithine, L-homoarginine, D,L-alpha-methylornithine, D,L-alpha-difluoromethylornithine) by rat pancreatic islets was compared to the ionic and secretory responses of the islets to the same amino acids. A tight correlation was found between the net uptake of these amino acids and their capacity to stimulate 86Rb efflux, 45Ca uptake and efflux, and insulin release. In the latter respect, there was little difference between metabolized and nonmetabolized amino acids. Thus, although L-homoarginine and 4-amino-1-guanylpiperidine-4-carboxylic acid failed to act as a substrate for either arginase or amino acid aminotransferase in islet homogenates, they both stimulated 86Rb efflux, 45Ca uptake and efflux, and insulin secretion in intact islets. These findings are compatible with the view that the accumulation of these positively charged amino acids in islet cells represents an essential determinant of their secretory action. Hence, the release of insulin evoked by these amino acids could be due to depolarization of the plasma membrane with subsequent gating of voltage-sensitive Ca2+ channels and/or to some other biophysical effect, as suggested by the persistence of a sizeable secretory response to L-arginine or L-ornithine in islets perifused at a high concentrations of extracellular K+ (50 mM).

• Research Organization: Brussels Free Univ. (Belgium)
• OSTI ID: 6540920
• Journal Information: Endocrinology; (United States), Journal Name: Endocrinology; (United States) Vol. 124:1; ISSN ENDOA
• Country of Publication: United States
• Language: English

Related Subjects

550201* -- Biochemistry-- Tracer Techniques
59 BASIC BIOLOGICAL SCIENCES
ALDEHYDES
ALKALI METAL ISOTOPES
ALKALI METALS
ALKALINE EARTH ISOTOPES
AMINES
AMINO ACIDS
AMINOTRANSFERASES
ANIMALS
ARGININE
AZINES
BETA DECAY RADIOISOTOPES
BETA-MINUS DECAY RADIOISOTOPES
BIOCHEMICAL REACTION KINETICS
BODY
CALCIUM 45
CALCIUM ISOTOPES
CARBOHYDRATES
CARBOXYLIC ACIDS
CATIONS
CHARGED PARTICLES
DAYS LIVING RADIOISOTOPES
DIGESTIVE SYSTEM
ELEMENTS
ENDOCRINE GLANDS
ENZYMES
EVEN-ODD NUCLEI
GLANDS
GLUCOSE
HETEROCYCLIC COMPOUNDS
HEXOSES
HORMONES
INSULIN
INTERMEDIATE MASS NUCLEI
IONS
ISOMERIC TRANSITION ISOTOPES
ISOTOPE APPLICATIONS
ISOTOPES
KINETICS
MAMMALS
METALS
MINUTES LIVING RADIOISOTOPES
MONOSACCHARIDES
NITROGEN TRANSFERASES
NUCLEI
ODD-ODD NUCLEI
ORGANIC ACIDS
ORGANIC COMPOUNDS
ORGANIC NITROGEN COMPOUNDS
ORGANS
ORNITHINE
PANCREAS
PEPTIDE HORMONES
PIPERIDINES
POTASSIUM
PYRIDINES
RADIOISOTOPES
RATS
REACTION KINETICS
RODENTS
RUBIDIUM 86
RUBIDIUM ISOTOPES
SACCHARIDES
SECRETION
TRACER TECHNIQUES
TRANSFERASES
UPTAKE
VERTEBRATES