Impact of chronic intermittent hypoxia upon rat liver lipid metabolism and interventional effect of Tempol

Abstract

To explore the impact of chronic intermittent hypoxia (CIH) upon rat liver lipid metabolism and effect of anti-oxidant Tempol. Male Wistar rats (n = 80) were randomly divided into intermittent hypoxia group (10, 20, 30, 40 times/h), intermittent hypoxia Tempol treatment group, intermittent hypoxia normal saline treatment group, intermittent air mimic group (IA) and blank control group (CG). Sections of liver were stained with hematoxylin and eosin. Serum levels of alanine aminotransferase (ALT) and aspartate aminotransferase (AST) were measured. Levels of liver homogenate triglyceride (TG), total cholesterol (TC), free fatty acids (FFA) and serum TG, TC, adiponectin (ADP) were measured. Liver histology: IH group exhibited hepatocellular swelling, hyperchromatosis, disrupted hepatocellular membrane. With the increase of frequency, there were local necrosis and infiltration of inflammatory cells. But no steatosis was seen. Tempol early treatment and IA groups exhibited no hepatocellular swelling or inflammatory cell infiltration. The activities of ALT and AST increased along with the increased frequency in IH group (all P < 0.01). The levels of ALT and AST in IH group ((48.6 ± 3.6), (25.4 ± 2.6) U/L) were higher than those in IA group ((20.3 ± 3.1), (18.7 ± 1.3) U/L) and CG group ((17.5 ± 2.4), (18.8 ± 1.3) U/L) (all P < 0.01). It decreased in Tempol treatment group, and more obviously when early intervention was applied (all P < 0.01). Liver homogenate TG, TC and FFA had no difference among IH, IA and CG groups (all P > 0.05), and no difference in different frequencies in IH group (all P > 0.05). The levels of serum TG, TC in IH groups were higher than those in IA and CG groups while ADP was lower (all P < 0.01). It changed more obviously in different frequencies in IH group (all P < 0.01). In Tempol treatment group, serum TG, TC decreased while ADP increased and changed more obviously when early intervention was applied (all P < 0.01). CIH causes the morphologic changes of liver and the elevations of ALT and AST, but results not in lipid deposition in liver cells. Anti-oxidation of Tempol can block intermittent hypoxia associated with liver injury.