Abstract
To assess further the role of insulin in alpha cell dysfunction in human diabetes mellitus, the glucagon response to intravenous arginine was studied in 5 noninsulin-dependent diabetics (NIDDM) and 5 insulin-dpendent diabetics (IDDM) whose blood gluose responses and plasma insulin simulated those in healthy subjects with the aid of the artificial beta cell system originally developed by us.
In both the 5 NIDDM and 5 IDDM, the blood glucose responses and plasma IRI after arginine challenge were made equivalent to those in healthy subjects with this system. Then, exaggerated glucagon responses were made completely similar to the response in healthy subjects.
These results strongly suggest that the abnormal glucagon responses to arginine observed in diabetes mellitus may be a consequence (either direct or indirect) of insulin lack, and perfect normalization of the response is achieved only when the plasma insulin concentration and glycemic control stimulate those of healthy subjects.
