title: Micellar electrokinetic chromatography method for measuring amino acid secretions from islets of Langerhans.
abstract: Islets of Langerhans are responsible for maintaining glucose homeostasis through regulated secretion of hormones and other factors. It is hypothesized that amino acids secreted from islets play a critical role in cell functionality and viability. For example, glutamate and gamma-aminobutyric acid have been proposed to work as paracrine signaling molecules within islets to coordinate the release of hormone secretion; other amino acids, such as glutamine, leucine, alanine, and arginine, have been shown to stimulate or potentiate glucose-stimulated insulin secretion. To characterize the potential roles that these small molecules may play in islet physiology, derivatization of amino acids in high-salt buffers commonly used in islet experiments with naphthalene-2,3-dicarboxaldehyde and MEKC separation conditions were optimized. The optimized conditions used d-norvaline as the internal standard and allowed quantification of 14 amino acids with LODs ranging from 0.2 to 7 nM. The RSDs of the migration times were 0.04-0.54% and the RSDs of the peak areas were 0.2-5.8% for the various amino acids. The effects of glucose and 2,4-dinitrophenol on amino acid secretions from islets were tested and a suppressive effect of glucose on gamma-aminobutyric acid release was observed, likely acting through adenosine triphosphate inactivation of glutamate decarboxylase.
authors.affiliation: Department of Chemistry and Biochemistry, Florida State University, Tallahassee, FL, USA.
authors.forename: Xue
authors.initials: X
authors.lastname: Wang
authors.affiliation: Department of Chemistry and Biochemistry, Florida State University, Tallahassee, FL, USA.
authors.forename: Lian
authors.initials: L
authors.lastname: Yi
authors.affiliation: Department of Chemistry and Biochemistry, Florida State University, Tallahassee, FL, USA.
authors.forename: Christelle
authors.initials: C
authors.lastname: Guillo
authors.affiliation: Department of Chemistry and Biochemistry, Florida State University, Tallahassee, FL, USA.
authors.forename: Michael G
authors.initials: MG
authors.lastname: Roper
mesh_terms: D019297:2,4-Dinitrophenol / Q000494:pharmacology; D000596:Amino Acids / Q000032:analysis* / Q000737:chemistry / Q000378:metabolism*; D000818:Animals; D020374:Chromatography, Micellar Electrokinetic Capillary; D005947:Glucose / Q000494:pharmacology; D007515:Islets of Langerhans / Q000187:drug effects / Q000378:metabolism*; D057230:Limit of Detection; D016014:Linear Models; D008297:Male; D051379:Mice; D015203:Reproducibility of Results
chemical_list: D000596:Amino Acids; D005947:Glucose; D019297:2,4-Dinitrophenol
keywords: 2,4-Dinitrophenol (DNP); CE; Glucose; LIF; Naphthalene-2,3-dicarboxaldehyde (NDA)