Abstract
IRI responses to successive pulses of arginine and glucose or glucose and arginine given at an interval of 30 minutes were investigated in healthy male volunteers under constant intravenous infusion of 5% glucose, 20% glucose or 10% arginine soultion for 2.5 hours.
The results were as follows:
1) On the infusion of 5% glucose solution during which the basal blood sugar remained within fasting levels, IRI increments (ΔIRI) induced by either arginine or glucose pulse were significantly enhanced by prior heterogenous pulses given 30 minutes before the pulse.
2) On the infusion of 20% glucose solution during which the basal blood sugar reached a level near 200 mg/100ml, IRI responses to arginine pulses were significantly increased compared withthose in the group with 5% glucose solution, irrespective of administration of a prior glucose pulse.
Synergism between arginine and glucose pulses in the induction of insulin secretion, however, was no longer observed in this group: neither glucose nor arginine as a prior heterogenous pulse significantly affected the IRI response to the second pulse.
3) During the infusion of 10% arginine solution, IRI response to glucose was significantly enhanced by a prior arginine pulse. 4) IRI increments induced by arginine pulses showed a significant correlation to the blood sugar levels at the time of arginine load.
