Abstract
Secrepan (Eisai Co. Tokyo, Japan) was administered to 9 healthy volunteers and 36 patients with non-insulin dependent diabetes mellitus (NIDDM) to clarify the effect of secretin on the pancreatic B-cell, by determining the changes in blood of insulin (IRI). Whereas IRI in healthy subjects showed a monophasic change, reaching a peak (ΔIRI=43±7.3μU/ml, M±SE) 5min after secretin loading and returning to the basal level in 15min, NIDDM patients on diet therapy (ΔIRI=40.2±7.6μU/ml) showed no significant difference from the con-trol group, but NIDDM patients on sulfonylurea (SU)(15.5±2.4μU/ml) and those on insulin therapy (5.3±1.4μU/ml), both showed a significant depression in responsiveness. Further, the changes in insulin secretion after atropine ad-ministration in healthy subjects and the changes in IRI response to Secrepan in vagotomized patients were also determined. As a result, data which pre-clude the possibility of association of the vagus nerve and cholinergic nerve with the stimulation of insulin secretion by secretin were obtained, and a direct action of secretin on the cell of islets of Langerhans was suggested.
The maximum IRI response after a secretin load had a significant positive correlation with the IRI response after a 75-gm GTT and the content of C-peptide immunoreactivity in 24-hour urine. Therefore, insulin response to a secretin load can be useful in assessing endogenous insulin secretion and pro-vides a pertinent clinical guide for the selection of an appropriate therapy for diabetes mellitus.
