Changes in glucagon processing occurring in the intestines of surgically stressed patients

BACKGROUND/AIMS: The kinetics of the pancreatic hormone glucagon in surgically stressed patients has not been investigated as thoroughly as that of insulin, despite its significant influence on energy metabolism in surgically stressed conditions. In the present study, we examined the kinetics of glucagon and glucagon-related peptides assessed by radioimmunoassay, and the molecular forms of these peptides using gel filtration chromatography, and in addition discuss glucagon processes in the pancreas and intestine in surgically stressed patients. METHODOLOGY: Ten patients who had undergone abdominal surgery for acute abdominal disorders were enrolled in this study (group S). Ten healthy volunteers were also enrolled as normal controls (group C). The serum level of glucagon and glucagon-related peptides were assessed in the early morning fasting state in both groups, on the second postoperative day in group S, using glucagon nonspecific N-terminal (glucagon-like immunoreactivity: GLI) and specific C-terminal (immunoreactive glucagon: IRG) radioimmunoassays. The molecular forms of these peptides were also estimated using the gel filtration chromatography method. RESULTS: Serum IRG in group S was significantly higher than that of group C (P < 0.05). Serum GLI was not significantly different between the two groups. In all patients except one in group S, a peculiar glicentin-like peptide (GLLP: MW about 8000) other than pancreatic glucagon was seen in gel filtration chromatography, which was not seen in group C. CONCLUSIONS: The kinetics and processing of glucagon in surgically stressed patients were quite different from those of healthy subjects. In surgically stressed patients, peculiar processing of glucagon occurred in the intestine, which was quite different from ordinary glucagon processing either in the pancreas or the intestine, generating GLLP.