Effect of High Fat Diet on Insulin Binding, 2-Deoxyglucose Uptake, and Glucose Oxidation in Rat Isolated Adipocytes

Abstract

Insulin binding 2-deoxyglucose uptake, and glucose oxidation were investigated using isolated adipocytes from rats fed a high fat (42.5%) diet (high fat diet rats) for 7 days, and those from rats fed normal laboratory chow (fat 4.5%).
In the adipocytes from high fat diet rats, insulin binding was decreased, and this decrease was caused by a decrease in receptor number.Insulin-stimulated 2-deoxyglucose uptake was decreased in the adipocytes from high fat diet rats.When the amount of 2-deoxyglucose uptake was plotted as a function of the amount of insulin bound, the curves from both groups were almost superimposable, suggesting that a coupling defect does not exist between receptor binding and the glucose uptake system in adipocytes from high fat diet rats.Glucose oxidation in the presence of various concentrations of insulin was decreased, and the dose-response curve of insulin for stimulation of glucose oxidation was shifted to the right in the adipocytes from high fat diet rats.
These abnormalities both at receptor and at post-receptor level play a causative role in the glucose intolerance observed in high fat diet rats.