Involvement of liver and skeletal muscle in sucrose-induced insulin resistance: dose-response studies.

Abstract

The ability of dietary sucrose to induce insulin resistance independent of changes in body weight is controversial. In the present study male rats were fed a high-starch (ST) diet (starch 68% of total kcal) ad libitum for 2 wk and then were fed equicalorically either the ST diet or a high-sucrose (SU) diet (sucrose 68% of total kcal) for 8 wk. Euglycemic, hyperinsulinemic (0, 1.2, 4.1, 8, 15 mU.kg-1.min-1, n = 6-8/group per dose) clamps were then used to establish dose-response relationships for glucose kinetics and metabolism. Body weight (513 +/- 3 g) and composition were similar between groups after the 8-wk dietary period. Glucose infusion rates (GIR; mg.kg-1.min-1) were significantly less in SU (0.9 +/- 5.8 +/- 0.6, 14.8 +/- 1.3, and 18 +/- 1.1) than in ST rats (4.1 +/- 0.9, 12.3 +/- 1.2, 22.6 +/- 1.5, and 25.9 +/- 1.8) at 1.2, 4.1, 8, and 15 mU.kg-1.min-1, respectively. Impaired suppression of endogenous glucose production accounted for 46, 43, 23, and 0% of the reduction in GIR in SU rats at 1.2, 4.1, 8, and 15 mU.kg-1.min-1, respectively. Despite basal hyperinsulinemia (38 +/- 2 microU/ml in SU vs. 26 +/- 2 microU/ml in ST rats), liver phosphoenolpyruvate carboxykinase (PEPCK) activity was 50% higher in SU than in ST rats and remained elevated in SU rats (by 30-40%) at the two lower insulin doses. No skeletal muscle glycogen accumulation occurred in SU rats at any of the insulin doses, and glycogen synthase I activity was significantly lower in SU rats at the two highest insulin doses.(ABSTRACT TRUNCATED AT 250 WORDS)

• Authors: M J Pagliassotti, K A Shahrokhi, M Moscarello
• Journal: The American journal of physiology (Am J Physiol) Vol. 266 Issue 5 Pt 2 Pg. R1637-44 (May 1994) ISSN: 0002-9513 [Print] United States
• PMID: 8203644 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't)

Chemical References

• Blood Glucose
• Dietary Carbohydrates
• Insulin
• Liver Glycogen
• Sucrose
• Glycogen

Topics

• Adipose Tissue (drug effects)
• Animals
• Blood Glucose (metabolism)
• Body Weight (drug effects)
• Dietary Carbohydrates
• Dose-Response Relationship, Drug
• Glucose Clamp Technique
• Glycogen (metabolism)
• Infusions, Intravenous
• Insulin (administration & dosage, blood, pharmacology)
• Insulin Resistance
• Liver (drug effects, physiology)
• Liver Glycogen (metabolism)
• Male
• Muscles (drug effects, physiology)
• Organ Size (drug effects)
• Rats
• Rats, Wistar
• Sucrose (pharmacology)