分子遺伝医学

Functional and Morphological Evaluation of the Mesenteric Artery, Kidney and Liver from Obese Rats: Impact of a High Fat Diet plus Fructose

Abstract

Thalita Rocha, Isabela Ressineti Mendes, Tatiana Mendes Costa, Amanda Gonçalves Ravos, Rudson A Ribeiro Oliveira, Mário Angelo Claudino and Fernanda Bruschi Marinho Priviero

Obesity is a worldwide problem of public health which is taking epidemic proportions. One of the main consequences of obesity is the development of cardiovascular diseases, which in turn, is the main cause of death in Brazil and in the world. Aim: To evaluate functional and morphological changes in the mesenteric artery, kidney and liver in obesity induced by high fat diet plus fructose. Methods: Male Wistar rats were submitted to a normolipidic diet (3.8% of fat–control group) or hyperlipidic diet (59% fat–HFD+F group) associated with fructose (100 mg/ml) in the drinking water during 12 weeks, starting at the 4th week of life. Initial and final body weight and epididymal fat, glucose tolerance and lipidic profile were evaluated. The superior mesenteric artery was removed for functional and histological analysis. Renal and hepatic functions were measured by plasma levels of specific metabolites and enzymes. The kidney and liver were also collected for histology. Results: In HFD+F group, it was observed increased body weight gain, epididymal fat and plasma levels of triglycerides while glucose tolerance was diminished. In the mesenteric artery, endothelium-dependent relaxation was reduced, with no changes in the endothelium-independent relaxation. Morphologically, no changes were seen in the vascular endothelium and smooth muscle. The kidney did not present functional and histological changes whereas the liver presented lipid accumulation, without changes on its function. Conclusion: Our data suggest that the high fat diet plus fructose induced endothelial dysfunction without structural changes on the vascular endothelium and smooth muscle. In this model of obesity, renal function and morphology were preserved while the hepatic tissue showed histological changes which are suggestive of a simple non-alcoholic steatosis.