Insulin binding and insulin response of adipocytes from rats adapted to fat feeding.
The effect of fat feeding on adipocyte insulin binding was examined to expand a study of adaptive changes in plasma membrane functions. Cells from rats fed a high fat (L) diet for five to seven days bound less insulin and showed a decreased response to insulin (glucose oxidation) compared to those from rats fed a high glucose (G) diet. Both high and low affinity sites were influenced; the extent of the binding difference increased as increasing concentrations of insulin were present in the assay medium. Diet did not change hormone degradation on the capacity of phospholipase C to increase binding. Concanavalin A effects on fat cells were also decreased by L diet both in inhibition of insulin binding and its insulin-like effect on glucose oxidation. Spermine, which had no effect on insulin binding, also had a smaller insulin-like effect on glucose oxidation by L cells than by G cells. Serum insulin was significantly lower (30 +/- 3.7 muU/ml) in L than in G (43 +/- 3.1 muU/ml) groups. Dietary fat produces alterations in fat cells that decrease insulin binding as a part of a complex overall adaptation to the diet.
D000273:Adipose Tissue / Q000166:cytology / Q000187:drug effects / Q000378:metabolism*; D000818:Animals; D001786:Blood Glucose / Q000378:metabolism; D001835:Body Weight; D003208:Concanavalin A; D004040:Dietary Carbohydrates; D004041:Dietary Fats; D005947:Glucose / Q000494:pharmacology; D006019:Glycolysis / Q000187:drug effects; D007328:Insulin / Q000097:blood / Q000378:metabolism* / Q000494:pharmacology; D007700:Kinetics; D008297:Male; D010740:Phospholipases; D051381:Rats; D011972:Receptor, Insulin / Q000378:metabolism*
D001786:Blood Glucose; D004040:Dietary Carbohydrates; D004041:Dietary Fats; D007328:Insulin; D003208:Concanavalin A; D011972:Receptor, Insulin; D010740:Phospholipases; D005947:Glucose