The aim of this study was to investigate the extent to which the basal steady state could be maintained with fixed concentrations of glucagon and insulin. To this end, arterial plasma glucose concentrations and peripheral glucose uptake (using the forearm technique) were compared in healthy men (age 19 to 23 years) in the normal postabsorptive state and after suppression of endogenous pancreatic secretion. Two groups (A and B), each consisting of four men, were studied. In group A, the study comprised a control period (I) of 40 minutes followed by a test period (II) of 180 minutes during which normal pancreatic secretion was maintained throughout. In group B, the study comprised a control period (I) of 40 minutes, a stabilization period (II) of 120 minutes, and a test period (III) of 120 minutes. After the control period with normal pancreatic secretion, a new steady state with fixed hormone concentrations was established during the first 90 minutes of period II using simultaneous infusions of somatostatin (250 micrograms/h), insulin (0.15 mU/kg/min) and glucagon, the latter being adjusted to maintain a stable arterial glucose level similar to the preceding control concentration. Thereafter, without further adjustment of the glucagon infusion rate, observations were continued during period III to assess the maintenance of the steady state. In group A, the range of variation in arterial glucose concentrations during periods I and II was 4.0 +/- 0.9 and 6.5 +/- 1.3 mg/dL, respectively.(ABSTRACT TRUNCATED AT 250 WORDS)