N. Shiga et al., THE RESPONSE OF GASTRIC-INHIBITORY POLYPEPTIDE (GIP) TO ORAL GLUCOSE IN CHRONIC-PANCREATITIS - A STUDY BY RADIOIMMUNOASSAY FOR HUMAN GIP, Biomedical research, 15(3), 1994, pp. 135-143
To investigate the insulinotropic effect of gastric inhibitory polypep
tide (GIP) in chronic pancreatitis (CP), we examined the GIP response
to 75 g oral glucose in 18 CP patients and 7 normal subjects (controls
) by a radioimmunoassay for human GIP. The GIP response of CP patients
was correlated with the pancreatic exocrine function which was evalua
ted by the caerulein-secretin test (CS test). Plasma GIP concentration
s following the oral administration of glucose were higher in CP patie
nts than in controls, but the difference was not significant. When CP
patients were divided into 3 groups according to their exocrine dysfun
ction (mild, moderate and severe), plasma GIP levels of CP patients wi
th severe exocrine dysfunction were significantly higher than those of
controls. No correlation was found between the volume and mean bicarb
onate concentration and plasma GIP level at 30 min after the glucose i
ngestion. Only the amylase output showed a negative correlation with p
lasma GIP level. A linear positive correlation was found between the i
ntegrated insulin and integrated GIP response's to oral glucose in CP
patients with severe exocrine dysfunction, whereas little correlation
was observed in those with milder exocrine dysfunction. These data sug
gest that in CP patients, endogenous GIP augments the insulin response
to oral glucose when pancreatic exocrine insufficiency progresses.