[Relations between portal and peripheral venous insulin, proinsulin and glucagon concentrations after oral glucose in...

During cholecystectomy a catheter was inserted into the V. porta via V. umbilicalis. 7 or 8 days later an oral glucose tolerance test was performed (100 g). Blood glucose, insulin (IRI), proinsulin-like material (PLM), and pancreatic glucagon (IRG) concentrations were determined in portal as well as in peripheral venous blood. 5 out of 6 patients showed a disturbed carbohydrate tolerance in comparison to 53 healthy subjects. The IRI increased promptly after the oral glucose load. The portal IRI-concentrations are significantly enhanced in comparison to the peripheral levels, but between both a positive correlation exists (r = 0.9447; p less than 0.01). PLM was slightly increased in the first 10 minutes. The basal IRG levels were not enhanced. Significant differences between the portal and peripheral IRG concentrations could not be observed. The correlation coefficient was 0.8902. Thus, the peripheral venous concentrations of IRI, PLM and IRG can be used as a diagnostic tool of pancreatic hormone secretion in man.