Adipocyte insulin responsiveness in female Sprague-Dawley rats fed a low fat diet containing a fat-mimetic carbohydrate.
Two experiments examined the effects of replacing high fat with low fat diets on adipocyte insulin sensitivity and response. Female Sprague-Dawley rats had free access to diets containing 21% (control), 61% (high fat) or 2% (low fat) of energy as fat. In the low fat diet a carbohydrate-based fat-mimetic carbohydrate replaced all but the essential fat present in the high fat diet. Insulin-stimulated glucose utilization by isolated adipocytes was measured after 10, 30 or 50 d. In a second study adipocyte insulin saturation curves were measured after 36 d. Rats fed the high fat diet for 30 d were insulin resistant and adipocyte basal and insulin-stimulated glucose utilization were depressed. The low fat diet initially stimulated glucose utilization of adipocytes but did not change insulin responsiveness. After 50 d there was no difference in glucose utilization between adipocytes from rats fed control and low fat diets. Insulin resistance in rats fed the high fat diet was associated with a nonsignificant reduction in insulin receptor number. These observations do not exclude the possibility of a post-receptor defect in glucose utilization.
Harris
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Nutrition Department, Kraft General Foods, Inc., Glenview, IL 60025.
D000273:Adipose Tissue / Q000187:drug effects* / Q000378:metabolism; D000818:Animals; D004040:Dietary Carbohydrates / Q000008:administration & dosage*; D004041:Dietary Fats / Q000008:administration & dosage*; D005260:Female; D005947:Glucose / Q000378:metabolism*; D007328:Insulin / Q000494:pharmacology*; D007333:Insulin Resistance; D007700:Kinetics; D050356:Lipid Metabolism; D051381:Rats; D011919:Rats, Inbred Strains
D004040:Dietary Carbohydrates; D004041:Dietary Fats; D007328:Insulin; D005947:Glucose