ISSN:
0263-6484
Keywords:
Hypothyroidism
;
pancreatic islets
;
FAD-glycerophosphate dehydrogenase
;
insulin secretion
;
Chemistry
;
Biochemistry and Biotechnology
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Biology
,
Medicine
Notes:
In thyroidectomized rats, the activity of FAD-linked glycerophosphate dehydrogenase was severely diminished in liver homogenates but not affected significantly in pancreatic islet homogenates, whilst the activity of 2-ketoglutarate dehydrogenase was decreased modestly in both liver and islet homogenates. Likewise, in intact islets of thyroidectomized rats, the generation of3HOH from [2-3H]glycerol was not decreased, and the ratio between oxidative and total glycolysis not significantly lower than in islets from sham-operated rats, at least in the presence of a high concentration of D-glucose. Nevertheless impaired oxidation of both D-[3,4-14C]glucose and D-[6-14C]glucose was observed in islets of thyroidectomized rats, the relative magnitude of such a decrease being more pronounced at a low than at a high D-glucose concentration. Such metabolic anomalies coincided with a lower level of plasma insulin and a decreased output of insulin by islets incubated at low (2·8 mM), but not higher, concentrations of D-glucose. It is concluded that hypothyroidism does not mimic the deficiency in islet FAD-linked glycerophosphate dehydrogenase activity found in rats with inherited or acquired non-insulin-dependent diabetes.
Additional Material:
2 Ill.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/cbf.290110211
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