Effect of Dexamethasone on Adipose Tissue and Liver Pyruvate Dehydrogenase and Its Stimulation by Insulin-Generated Chemical Mediator*
- 1 January 1984
- journal article
- research article
- Published by The Endocrine Society in Endocrinology
- Vol. 114 (1), 99-107
- https://doi.org/10.1210/endo-114-1-99
Abstract
Rats were treated with dexamethasone (50 .mu.g/day, s.c.) for 4 days [glucocorticoid administration results in insulin resistance]. Total pyruvate dehydrogenase (PDH) and insulin-stimulated PDH 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 mitochondrial 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. Apparently 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.This publication has 4 references indexed in Scilit:
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