Effect of dexamethasone on adipose tissue and liver pyruvate dehydrogenase and its stimulation by insulin-generated chemical mediator
Rats were treated with dexamethasone (50 micrograms/day, sc) for 4 days. Total pyruvate dehydrogenase (PDH) and insulin-stimulated PDHa activities were decreased in fat pads from dexamethasone-treated rats compared to control values. Coincubation experiments with adipocyte mitochondria, plasma membr...
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Published in | Endocrinology (Philadelphia) Vol. 114; no. 1; p. 99 |
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Main Authors | , , |
Format | Journal Article |
Language | English |
Published |
United States
01.01.1984
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Subjects | |
Online Access | Get more information |
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Summary: | Rats were treated with dexamethasone (50 micrograms/day, sc) for 4 days. Total pyruvate dehydrogenase (PDH) and insulin-stimulated PDHa activities were decreased in fat pads from dexamethasone-treated rats compared to control values. Coincubation experiments with adipocyte mitochondria, plasma membrane, and insulin demonstrated decreased stimulation of PDH in preparations from dexamethasone-treated rats. The responsiveness of the mitochondrial PDH system to insulin and control rat plasma membranes was not different in glucocorticoid-treated adipocyte preparations compared to controls. Liver mitochondria from dexamethasone-treated rats demonstrated decreased basal enzyme activity and a decreased percentage of stimulation of PDH when supernatants from insulin-exposed liver particulate fractions were tested. These experiments suggest that insulin resistance produced by glucocorticoid treatment, like that resulting from fat feeding, is accompanied by a decrease in the capacity of adipocyte and liver plasma membranes to generate PDH activator in response to insulin. |
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ISSN: | 0013-7227 |
DOI: | 10.1210/endo-114-1-99 |