Lack of a "big plasma glucagon" response during arginine stimulation of glucagon secretion

In order to determine whether the concentration of "big plasma glucagon" (BPG) levels changes in response to stimulation of the pancreatic A-cell, plasma samples were obtained from eight Type II diabetics before and during arginine infusion. The BPG and pancreatic glucagon (IRG3,500) components of glucagon were separated by gel filtration chromatography and fractions were assayed for immunoreactive glucagon (IRG) with 30K antisera. When chromatograms from basal and stimulated plasma were compared, no changes in BPG were observed, demonstrating that only IRG3,500 is involved in the increase in IRG observed in these patients.