The peculiar processing of glucagon and glucagon-related peptides in patients after pancreatectomy.
OBJECTIVE
Although, glucagon has been detected even in the serum of totally pancreatectomized patients and the origin was suggested to be the intestine, the kinetics of glucagon is not well known after pancreatectomy. In this study, we investigated the kinetics of glucagon and glucagon-related peptides and discuss the glucagon processes in the pancreas and intestine in pancreatectomy patients.


METHODS
Seven patients who had undergone pancreatoduodenectomy reconstruction using Child's procedures (distal pancreatojejunostomy, choledochojejunostomy and gastrojejunostomy) (group PD) and five patients who had undergone distal pancreatectomy (group DP) served as the subjects of this study. In addition to these two groups, five patients who had undergone gastrectomy reconstructions using the Billroth II procedure (group GX), to examine whether the alimentary tract reconstructions themselves would have any effect on the kinetics of glucagon, and 10 normal subjects (group C) were also enrolled in this study. All patients received a 75-g oral glucose tolerance test in the early morning fasting state. Serum glucagon levels were assessed using the glucagon non-specific N-terminal (glucagon-like immunoreactivity: GLI) and specific C-terminal (immunoreactive glucagon: IRG) radioimmunoassays. The molecular forms of these glucagon-related peptides were also estimated using the gel filtration chromatography method before and after the 75-g oral glucose load.


RESULTS
After the glucose load, serum GLIs were increased significantly in groups GX and PD suggesting that these were affected by the alimentary tract reconstructions. Serum IRGs including true pancreatic glucagon were slightly increased in groups PD and DP after oral glucose load suggesting that these paradoxical responses might be associated with the glucose tolerance deficiencies observed in both groups, but not associated with the alimentary tract reconstruction.


CONCLUSIONS
The paradoxical rise of IRGs based on the findings of gel filtration chromatography were possibly due to the generated peculiar glicentin-like peptide and pancreatic glucagon from the glucagon precursor, preproglucagon, after pancreatectomy, which is processed in association with the glucose tolerance deficiencies after pancreatectomy.
Tanjoh
Katsuhisa
K
Department of Emergency and Critical Care Medicine, Nihon University School of Medicine, 30-1 Ohyaguchi Kamimachi, Itabashi-ku, Tokyo, 173-0032, Japan. k.tanjoh@jcom.home.ne.jp
Tomita
Ryouichi
R
Hayashi
Nariyuki
N
D000368:Aged; D002850:Chromatography, Gel; D005260:Female; D005934:Glucagon / Q000097:blood*; D004763:Glucagon-Like Peptides; D006801:Humans; D008297:Male; D008875:Middle Aged; D010180:Pancreatectomy; D010187:Pancreatic Hormones / Q000378:metabolism*; D010455:Peptides / Q000378:metabolism*; D011184:Postoperative Period; D011498:Protein Precursors / Q000378:metabolism*; D011863:Radioimmunoassay
D010187:Pancreatic Hormones; D010455:Peptides; D011498:Protein Precursors; D004763:Glucagon-Like Peptides; C015236:glucagon-like-immunoreactivity; D005934:Glucagon