ISSN:
1432-0428
Keywords:
BB rat
;
diabetes
;
glucose intolerance
;
insulin sensitivity
Source:
Springer Online Journal Archives 1860-2000
Topics:
Medicine
Notes:
Summary In diabetes-prone BB rats, 30 to 50% of animals undergo autoimmune destruction of the pancreatic B-cells leading to a short period of glucose intolerance, followed by an abrupt onset of diabetes. We have examined whether the glucose intolerance period and the onset of diabetes are associated with changes in insulin sensitivity, using the euglycaemic hyperinsulinaemic clamp coupled with [3-3H] glucose infusion. Glucose intolerant rats were detected by a transient glycosuria one hour after an oral glucose load performed every four days. Insulin sensitivity studied in these rats the day following their detection was normal. Other diabetes-prone BB rats were tested daily and studied on the first day of glycosuria. In the basal state, glucose production was increased in diabetic rats (11.3±1.1 vs 7.1±0.8mg·min−1·kg−1, p〈0.05). Tissue glucose utilization was similar in diabetic and control rats (8.3±0.5 vs 7.1±0.8mg·min−1·kg−1) despite a three fold higher glycaemia in the diabetic rats. During the hyperinsulinaemic clamps, glycaemia was clamped at 6.1–6.6 mmol/l in diabetic and control rats. A decreased insulin sensitivity was observed in diabetic rats at submaximal (200 μU/ml) and maximal (1500 μU/ml) insulin concentrations for both inhibition of hepatic glucose production and stimulation of glucose utilization. No autoantibodies against insulin could be detected in the plasma of diabetic rats. Plasma concentrations of glucagon, catecholamines, ketone bodies and fatty acids were similar in control and diabetic rats during the clamp studies. Our results suggest that the decrease of basal insulin concentration is responsible for the insulin resistance in the diabetic BB rat at onset of diabetes, either directly or through the increased glycaemia.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00297448
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