A comparative study of amino acid consumption by rat islet cells and the clonal beta-cell line BRIN-BD11 - the functional significance of L-alanine.
Evidence has been published that L -alanine may, under appropriate conditions, promote insulin secretion in normal rodent islets and various beta cell lines. Previous results utilising the clonal beta-cell line BRIN-BD11, demonstrated that alanine dramatically elevated insulin release by a mechanism requiring oxidative metabolism. We demonstrate in this paper that addition ofL -alanine had an insulinotropic effect in dispersed primary islet cells. Addition of D -glucose increasedL -alanine consumption in both BRIN-BD11 cells and primary islet cells.L -glutamine consumption in the BRIN-BD11 cell line and primary rat islets was also determined. The consumption rate was in line with that previously reported for cells of the immune system and other glutamine-utilising cells or tIssues. However,L -alanine consumption was at least an order of magnitude higher thanL -glutamine consumption. The metabolism ofL -alanine in the beta-cell may result in stimulation of insulin secretion via generation of metabolic stimulus secretion coupling factors such asL -glutamate.
Dixon
G
G
Department of Biochemistry, Conway Institute of Biomolecular and Biomedical Research, University College Dublin, Belfield, Dublin 4, Ireland.
Nolan
J
J
McClenaghan
N
N
Flatt
P R
PR
Newsholme
P
P
D000255:Adenosine Triphosphate / Q000378:metabolism; D000409:Alanine / Q000378:metabolism* / Q000494:pharmacology / Q000502:physiology; D000818:Animals; D002460:Cell Line; D002999:Clone Cells / Q000187:drug effects / Q000378:metabolism; D004305:Dose-Response Relationship, Drug; D005260:Female; D005947:Glucose / Q000494:pharmacology; D018698:Glutamic Acid / Q000378:metabolism; D005973:Glutamine / Q000378:metabolism; D007328:Insulin / Q000378:metabolism; D007515:Islets of Langerhans / Q000187:drug effects / Q000378:metabolism*; D051381:Rats; D017208:Rats, Wistar
D007328:Insulin; D005973:Glutamine; D018698:Glutamic Acid; D000255:Adenosine Triphosphate; D005947:Glucose; D000409:Alanine