Perfil em ácidos graxos do fígado e sua relação com a esteatose hepática e o perfil lipídico sérico de ratos submetidos a diferentes dietas padrão

Abstract

Hepatic steatosis (HS) is characterized by accumulation of lipids in the cytoplasm of hepatocytes, which exceeds 5% of liver weight. Occurs due to failure of normal hepatic lipid metabolism due to a defect within the hepatocyte or the supply of fatty acids (FA) or excess carbohydrates to the liver, exceeding the capacity of the secretion of lipids in the cell. The HS was once considered a benign event, however, this condition is capable of triggering a broad spectrum of clinical and pathological manifestations, such as nonalcoholic steatohepatitis, which may progress to cirrhosis in up to 25% of cases. In studies with experimental animals, dietary changes may induce the HS, however, in previous work by this research group, hás been found the appearance of fatty infiltration in animals fed with standard diets, free of modifications. To contribute to the discussion of the problem, this paper presents a literature review chapter titled fatty acids and nonalcoholic fatty liver disease that in addition to discussing the role of different FA in the context of nonalcoholic fatty liver disease, treating especially the possible relationship to the etiology, progression and / or reversal of HS, discusses the pathogenesis and disease progression. And an article by results entitled fatty acid profile of the liver and its relation to hepatic steatosis and serum lipid profile in rats fed with different standard diets, an experimental study with rats exposed to different standard dietary. In this study, 40 male weanling Wistar rats were divided, depending on the type and duration of exposure to diets in: AIN-93 1m and AIN-93 4m (on AIN-93 diet for 1 or 4 months) and DCo 1m and DCo 4m (under chow diet for 1 or 4 months) groups. Blood was collected for biochemical analysis and after sacrificing the animals, the liver tissue was removed for histology and subsequent solvent extraction of fatty acids, which were methylated with BF3/methanol. The analysis of methyl esters of fatty acids was performed by gas chromatography-mass spectrometry. The HS was found in 90% and 100% of the animals in AIN-93 1m and AIN-93 4m groups, respectively, 20% of the animals DCo 4m group and none in the DCo 1m. The serum lipid profile and serum markers of function and injury liver, other than glycemia, did not seem to be related to HS. Analysis of the absolute weight and relative liver, in turn, showed the importance of the HS to growth the organ of the animals. The FA heptadecanoic and arachidonic seem to be related to exposure to different diets. The levels of oleic acid were higher and of stearic lower in the groups exposed to the diet AIN-93, idependent of the exposure time. No difference was observed for the other FA. The different diets influence on the profile in FA hepatic tissue of animals. This profile was related to the observed HS, particularly in relation to FA oleic and stearic acids, as well as associations between oleic, stearic, palmitic and palmitoleic with the degree of HS, with possible repercussions on the prognosis of the disease.