A growing number of studies indicate an association between obesity, insulin resistance, dyslipidaemia and cardiovascular disorders, collectively known as Syndrome X. In this study we have aimed to produce a model of Syndrome X by voluntary feeding of Wistar rats with a highly palatable cafeteria diet, and examined its effects on metabolic changes and vascular reactivity of Wistar rats. At the end of the experiment, the cafeteria-diet fed group was divided into two groups of low weight gain (LWG) and high weight gain (HWG). Both LWG and HWG groups had significantly (P < 0.01) higher fat-pad mass than their chow-fed counterparts, while gastrocnemius muscle mass were comparable. All cafeteria-diet fed rats had significantly (P < 0.01) raised plasma triacylglycerol (TG) levels whereas plasma non-esterified fatty acids, glucose and insulin levels were similar between chow-fed and cafeteria-diet fed rats. Vasorelaxation responses to acteylcholine, insulin and sodium nitroprusside were significantly (P < 0.01) attenuated in cafeteria-diet fed animals; however, there were no differences in contractile responses of the mesenteric arteries to noradrenaline or KCl between the groups. Multiple regression analysis showed a significant (P < 0.05) negative association between plasma TG levels and reduction in acetylcholine-induced vasorelaxation. Acetylcholine-induced vasorelaxation was also significantly (P < 0.05) associated with the amount of fat-pad mass. These data suggest that diet-induced vascular dysfunction can occur in the absence of insulin resistance, and that plasma TGs may have a detrimental effect on vascular reactivity.
Diet-induced endothelial dysfunction in the rat is independent of the degree of increase in total body weight
Ebrahim K. NADERALI, Lucy C. PICKAVANCE, John P. H. WILDING, Gareth WILLIAMS; Diet-induced endothelial dysfunction in the rat is independent of the degree of increase in total body weight. Clin Sci (Lond) 1 June 2001; 100 (6): 635–641. doi: https://doi.org/10.1042/cs1000635
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