Experimental models of metabolic syndrome in rats

Abstract

Metabolic syndrome (MS) is a disorder comprising central obesity, dyslipidemia, raised blood pressure, insulin resistance. The aim of the present study was to develop a cheap, easy and reproducible rat model of MS. 36 male Wistar rats were divided in 3 groups: a control group (C) receiving regular rat chow diet, a high-fat (HF) group receiving lard enriched rat chow and a high-fat high-fructose (HFHF) group receiving lard and fructose enriched rat chow. HF and HFHF groups had also 10% fructose in their drinking water. The duration of the study was 8 weeks. Body weights were measured weekly. At the end of the study insulin tolerance test (ITT) was performed. Liver and fat weight index were measured after sacrifice. Lipid biochemical parameters and insulin concentration in serum were determined. Liver triglycerides (TG) were measured. The oxidative stress in serum was assessed by thiobarbituric reactive substances (TBARS). At the end of the study the animals did not differ in their body weights across the groups, but the fat index in both HF and HFHF groups was higher. Plasma TG and cholesterol were raised in both groups and the ratio cholesterol/ HDL-cholesterol was higher. Liver TG were elevated in HFHF rats. ITT revealed reduced insulin sensitivity in both experimental groups although serum insulin was elevated only in HFHF group. TBARS were increased in both HF and HFHF groups. Both models displayed most of the features of MS; the HFHF probably better reflects the ‘cafeteria’ diet and its unhealthy consequences.