Diabetes, Vol 34, Issue 11 1120-1126, Copyright © 1985 by American Diabetes Association
In vivo hepatic and peripheral insulin sensitivity in rats with non-insulin-dependent diabetes induced by streptozocin. Assessment with the insulin-glucose clamp technique
M Kergoat and B Portha
Non-insulin-dependent diabetes mellitus (NIDDM) was obtained in adult
female rats by neonatal administration of streptozocin (STZ). At 2 mo of
age, the basal plasma glucose values in the postabsorptive state were
elevated, the glucose disappearance rate measured after intravenous (i.v.)
glucose load was significantly lower in the diabetic than in control rats,
and in vivo glucose-induced insulin release was drastically reduced. To
quantify and characterize the in vivo insulin sensitivity in rats with
NIDDM, we have used the insulin-glucose clamp technique. The effects of
different concentrations of insulin on glucose production, glucose
utilization, and glucose clearance (measured by using 3-3H-glucose) were
studied in anesthetized diabetic or control rats while in the
postabsorptive state. An inherent condition to set up a valid experimental
design was to take into consideration, in the diabetics, the influence of
the high blood glucose concentration on glucose uptake and glucose
production, since the blood glucose concentration by itself affects these
two parameters by a mass action effect independent of insulin. The issue
was addressed by evaluating glucose production and utilization in three
experimental groups: diabetics clamped at their basal blood glucose level
(170 mg/dl), controls clamped at their basal blood glucose level (110
mg/dl), and controls clamped at high blood glucose level (170 mg/dl). In
the basal state, glucose production was significantly higher in the
diabetics than in controls. When plasma insulin was clamped at submaximal
levels (300 microU/ml), the suppression of glucose production was
significantly more important in the diabetics than in the two control
groups.(ABSTRACT TRUNCATED AT 250 WORDS)