Effect of high sucrose feeding on fat accumulation in the male Wistar rat

High sucrose intake is generally thought to be a risk factor for obesity and insulin resistance. We examined the effects of feeding sucrose on fat accumulation and insulin release in male rats. Six-week-old male Wistar rats were maintained on a high sucrose diet for 4 or 12 weeks. Control rats were fed a diet based on starch. No significant difference in daily caloric intake or weight gain existed between the two dietary groups. There was no difference between the two dietary groups in the gain of abdominal subcutaneous fat (SC) at 4-week. In contrast, rats fed the high sucrose diet had significantly more mesenteric fat (MES) than controls (p < 0.01). At 12 weeks, rats fed the high sucrose diet had significantly more SC and MES than controls (SC: p < 0.05, MES: p < 0.01). Basal immunoreactive insulin (IRI) concentrations in the portal vein (PV) of rats fed the high sucrose diet was significantly higher compared to those of controls (4 wk: p < 0.05, 12 wk: p < 0.05). No difference between the two dietary groups in basal IRI concentrations in the inferior vena cava (IVC) existed at 4 weeks; whereas at 12 weeks, the basal IRI concentrations in the IVC in rats fed the high sucrose diet were significantly higher than in controls (p < 0.05). The mesenteric and subcutaneous fat accumulations were closely related to hyperinsulinemia in the portal vein and inferior vena cava, respectively. Twelve weeks of high sucrose feeding caused accumulation of abdominal adipose tissue with marked hyperinsulinemia and hyperlipidemia. Our study is the first to demonstrate that abdominal fat induced by high sucrose intake in male rats is accompanied by an abnormal metabolic state similar to an insulin-resistant state.