Distribution of plasma glucagon immunoreactivity in a patient with suspected glucagonoma.
Gel filtration of plasma from a patient with a clinical syndrome of glucagonoma and  a total plasma glucagon level of 2600 pg/ml, revealed the four glucagon immunoreactive fractions found in normal subjects. The total hyperglucagonemia observed was due to high levels of true glucagon and proglucagon moieties. The so-called "big plasma glucagon" (BPG) measured 190 pg/ml (normal average 113 +/- 79 pg/ml, Mean +/- SD, N = 10); the large glucagon immunoreactivity, LGI (9000 mol wt), measured 625 pg/ml (normal average 11 +/- 16 pg/ml); the true glucagon accounted for 1435 pg/ml (normal average 31 +/- 29 pg/ml); and the small glucagon immunoreactive fraction (approximately 2000 mol wt) measured 35 pg/ml (normal average 26 +/- 18 pg/ml). The high levels of LGI, considered a candidate for proglucagon, may reflect the increased secretory activity of the tumor.
D007516:Adenoma, Islet Cell / Q000097:blood / Q000378:metabolism*; D000941:Antigens / Q000032:analysis*; D001786:Blood Glucose / Q000032:analysis; D005260:Female; D005934:Glucagon / Q000097:blood* / Q000276:immunology / Q000378:metabolism; D006801:Humans; D007328:Insulin / Q000097:blood; D008875:Middle Aged; D008970:Molecular Weight; D010190:Pancreatic Neoplasms / Q000097:blood / Q000378:metabolism*
D000941:Antigens; D001786:Blood Glucose; D007328:Insulin; D005934:Glucagon