Lipogenic enzyme activities and glucose uptake in fat tissue of dyslipemic, insulin-resistant rats: Effects of fish oil

Abstract

Objective: The purposes of the present work were twofold: (1) investigate same mechanisms involvedin the development of fat cell hypertrophy in the experimental model of dyslipidemia andwhole-body insulin resistance induced in rats chronically fed a sucrose-rich diet (SRD); and (2) analyzethe possible beneficial effect of fish oil on these mechanisms.Methods: For 6 mo, male Wistar rats received a sucrose-rich diet (62.5% w/w sucrose, 8% corn oil)or a control diet in which sucrose was replaced by starch. After this period, the sucrose-fed animalswere divided randomly into two groups: the first one continued with the same diet up to 8 mo andthe second one received the same diet, but with corn oil replaced by 7% fish oil þ 1 % corn oil.Rats were fed with this diet for the next 2 mo.Results: Although an enlarged fat cell lipolysis and an impaired insulin-stimulated glucose uptakewere present in the fat cells of SRD-fed rats, an increase of several key enzymes of the novo lipogenesiscould be one of the possible mechanisms involved in visceral adiposity. The addition of dietaryfish oil restored or improved the above abnormalities.Conclusion: This study shows possible mechanisms conditioning the influence of nutrients on thedevelopment and management of dyslipidemia, insulin sensitivity, and fat cell accretion, all abnormalitiespresent in the metabolic syndrome.