STIMULUS-SECRETION COUPLING OF ARGININE-INDUCED INSULIN RELEASE - RESISTANCE OF ARGININE-STIMULATED AND ORNITHINE-STIMULATED GLUCAGON AND INSULIN RELEASE TO D,L-ALPHA-DIFLUOROMETHYLORNITHINE

In the isolated perfused rat pancreas, d,l-difluoromethylornithine, tested at a concentration of 3 mmol/L, failed to affect the release of glucagon and insulin caused, over 15 min stimulation, by either l-arginine or l-ornithine (2.0, 5.0 or 10.0 mmol/L) in the presence of either 3.3 or 5.6 mmol/L d-glucose. The inhibition of ornithine decarboxylase also failed to affect the release of glucagon provoked by either l-leucine (2 or 3 mmol/L) or l-glutamine (2 mmol/L) and the secretion of insulin stimulated by a rise in glucose concentration from 5.6 to 10.6 mmol/L. These data are interpreted to suggest that the rapid generation of polyamines from either l-arginine or l-ornithine does not play any significant role in the immediate glucagonotropic and insulinotropic action of these cationic amino acids. © 1990.