Indomethacin-induced augmentation of insulin release

The effect of indomethacin, a potent prostaglandin synthetase inhibitor upon portal venous glucose, glucagon, and insulin, was examined in eight glucose-loaded, nondiabetic adult male mongrel dogs, by examining the response of each animal to a standard enteral glucose challenge with and without indomethacin pretreatment. Mean portal venous insulin rose after glucose loading with the rise after indomethacin pretreatment being significantly greater (P < 0.001) and more prolonged than that seen in the control group. Mean basal glucagon was increased with indomethacin pretreatment relative to controls (P < 0.01) and remained so throughout the measurement period. The glucose tolerance curves generated in control and indomethacin pretreatment groups were of normal contour and magnitude, and indistinguishable from one another. The effects seen are presumably the consequence of prostaglandin synthetase inhibition and imply that prostaglandins may play a suppressor role in modulating the insulin response to a glucose challenge.