Plasma pancreatic glucagon in pancreatic and primary diabetes, and liver cirrhosis: application of a correction to the radioimmunoassay for pancreatic glucagon

Abstract

Evidence is present that plasma contains non-specific factors which interfere with the 30K glucagon assays. A correction can be made for these interference factors because the factors can be quantitated following absorption of glucagon with charcoal-dextran. Using a correction factor the range of fasting plasma immunoreactive glucagon (IRG) in 12 totally pancreatectomized patients was below detectable limit. Fasting levels of IRG were determined on the plasma from 25 liver cirrhotics complicated by abnormal GTT, 13 pancreatic diabetics with chronic calcified pancreatitis (CCP), 25 adult-onset primary diabetics and 25 healthy subjects. When all samples were measured using no correction factor, the mean levels of IRG were 358 +/- 24 (mean +/- SE), 170 +/- 26, 178 +/- 16 and 178 +/- 7 pg/ml, respectively. Using a correction factor the mean level of IRG were 177 +/- 26, 16 +/- 4, 39 +/- 9 and 20 +/- 4 pg/ml, respectively. The mean values of the interference factor were not significantly different among all five groups. During an arginine infusion the interference factor remained unchanged despite an increase in IRG. It is available but not always necessary to apply a correction factor for 30K glucagon radioimmunoassay.